jul 2006 / last mod dec 2017 / greg goebel

* 21 entries including: waterworks infrastructure, a history of the slide rule, another road trip, Texas wind power, extreme weight measurements, internet server farms, smart space probes, games on cellphones, shrewd Hugo Chavez, Russian Moon probes, cellphones in Africa, ID theft exaggerated, air traffic control controversy, SOP superchips, Japanese assertiveness, and electricity-producing bacteria.

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* THE RISE & FALL OF THE SLIDE RULE (2): The real irony in the 17th-century invention of the slide rule was that it was then generally ignored for about two centuries, despite the fact that log tables were in general use through that era. Briton Peter Roget, who originated the famous thesaurus that bears his name, demonstrated a relatively advanced slide rule to the British Royal Society in 1814, but it wasn't until 1850 that the idea finally started to catch on, when a French lieutenant of artillery named Amedee Mannheim introduced a slide rule with auxiliary scales and a "cursor", or slider with pointers to help nail down the numbers being read on the rule. The French Army correctly thought it would help gunners compute the trajectory of their fire and formally adopted Mannheim's gadget.

By World War II, every engineer had a slide rule with a transparent cursor and auxiliary scales. The auxiliary scales were actually just lookup tables. For example, determining cube roots and square roots really just involved placing three log scales next to each other, with three log cycles on the first scale, two on the second, and one on the third:

   1         10       100       1000
   |         |         |         |

   1              10            100
   |              |              |

   1                             10
   |                             |

The bottom scale gives the cube root of the top scale and the square root of the middle scale; of course, the top scale similarly gives the cube of the bottom scale and the middle scale gives the square of the bottom scale.

It was also possible to provide lookup scales for reciprocals; tangent and cotangent (the same scale could be double-labeled to serve both); sine and cosine (again, one scale with double labels); and the actual values of logs corresponding to the antilogs that the calculating scales were marked in. Fancy slide rules had even more scales. Important values like PI or "e" were marked on the scales. Late-model circular slide rules might be mounted on a rectangular plate with useful reference data printed on the otherwise unused backside, or even fitted with insert cards with more reference data.

circular slide rule

A longer slide rule gave a table that could be read more exactly, and in 1921 a London engineer named Otis King wrapped a 1.5 meter (5 foot) scale in a helix around a cylinder 2.5 centimeters (an inch) in diameter, yielding a high-precision device that could be carried in a pocket. The Fuller slide rule took this determination for precision to a practical limit, resulting in a device that looked like a really elaborate baker's rolling pin with a coiled-up 12.5 meter (41 foot) scale.

* The historical importance of the slide rule almost cannot be overemphasized. It was used to design the Empire State Building, the Golden Gate Bridge, Hoover Dam, the first transistor radios, the 707 jetliner, and even to a large degree the Saturn V booster that put Americans on the Moon. The Saturn V was developed by a team under German rocket scientist Wernher von Braun, who liked the relatively plain but precise German Nestler slide rule. His opposite number, Soviet "Chief Rocket Designer" Sergei Korolyev, also liked the Nestler, as did Albert Einstein. Most American engineers preferred the Pickett slide rule, and astronauts carried Picketts to the Moon as backup computing power -- so the 1950s sci-fi writers weren't completely off base.

Slide rules designed to perform specialized calculations were also built. During World War II, the US Navy developed a generic slide-rule "chassis" with an aluminum body and plastic cursor that could be "programmed" by fitting it with a properly marked celluloid card. An aircraft navigator, for example, could use such a device to calculate fuel consumption and range. In their postwar prime, it was nothing unusual to find little specialized circular slide rule-like devices made of plastic to perform calculations such as interest rates, though they were often just simple lookup tables. They were given away as promotional items.

* The fall of the slide rule was abrupt. It was a marvelous device, but it had several weaknesses. One was that it was all but useless as an adding machine. A second was that most slide rules were limited to three digits of precision, with the really fancy ones getting five digits. A third was that the user had to keep track of the decimal point, determining if the answer read as 0.375 on the slide rule was 3.75, 3,750, 0.00375, or whatever. A good slipstick operator was skilled at mentally performing rough calculations.

Electronic calculators began to emerge during the 1960s, but it wasn't until 1972 that Hewlett-Packard Company introduced the HP-35, the first pocket handheld digital electronic calculator. According to HP company legend, when the revered Bill Hewlett was playing with a prototype, a marketing person asked: "Who'll buy it?!" -- Hewlett replied: "I will. Build it."

There were those who still thought the slide rule was good enough, particularly when the HP-35 cost $395 USD, but HP made big money with it. By the end of the decade pocket scientific calculators were cheaper and more powerful, with programmable capabilities. The slide rule had all but died by then. Pickett and the other slide rule manufacturers died with it.

Anyone who actually ever used a slide rule still remembers it with a certain respect, as a device that combined the simplest possible mechanics with a surprising degree of power. It was both simple and extremely smart. Along with that respect comes a certain wry humor in considering the modern generation; any mention of a slide rule gets a look from them that suggests the user is a dusty fossil from centuries past.

* ED: I was in the last generation to use the slide rule. I used one in high school, the circular slide rule with tables in the image above was the exact type I had. I did a hitch in the Army after I graduated, and by the time I was in college the transition to handheld calculators was complete.

I wanted to see if I could find a website with a collection of the little freebie promotional calculators they used to hand out when I was a kid. They usually consisted of a wheel or slide or two inside a stiff plastic envelope with a port to reveal the answer. After some poking around, I came up with a reference to "slide charts", which described them perfectly. They're effectively application-specific calculators, according to one of the sites that discuss them: "Engineers use slide rules, technicians use slide charts."

classic slide chart

Sometimes they only amount to look-up tables, with the sliding format simply making it easier to sort out a desired entry from the clutter -- though some of them do use slide rule principles to perform calculations. I use the present tense, because somewhat to my surprise they're still an active business, with a number of firms able to cook up custom slide charts on request. Makes sense they're still alive -- I ran across a firm that also makes applications-specific electronic calculators, and they run about an average of fifty bucks apiece. Even a fancy slide chart made in a modest batch comes in at well under a dollar. [END OF SERIES]



* INFRASTRUCTURE -- WATERWORKS (6): A civic water system not only has to get water to end users, it must handle the waste water -- sewage -- generated by those users, as well as drain the rain that pours down in storms and keep the streets from being flooded.

A municipal sewage system is a bit trickier to design than a water supply system. The problem is that sewage lines are rarely full, so the lines themselves can't be pumped, and that means the sewage has to flow by the hydraulic grade. In addition, since the sewage contains, ah, "solids", the grade has to be steep enough to keep the sewage flowing, with steeper grades around curves where the solids could accumulate and block the sewer line.

Usually sewer pipes are buried more deeply than any other utilities. The end-user lines are called "laterals", which dump into "submains", which dump in turn into "mains", "trunks", and "interceptors". The network feeds a sewage treatment plant, which is often sited on the lowest ground in town. Small sewage pipes are made of "vitrified clay", which looks like a glazed brick material, with the smooth surface helping prevent blockages and erosion. Large sewer mains are cast in concrete segments; they do not have smooth surfaces, but are wide enough so that clogging is much less of a threat and are rugged enough to resist erosion.

Sometimes it's impossible to build the entire sewage network on the hydraulic grade, and so a subnet feeds a sump or "wet well", which is pumped into the rest of the network through a pumping station. The pumps, which are set up in a separate "dry well" to make them less messy to maintain, have to be robust, once again because of "solids". The electric motors for the pumps are on the surface above the dry well, along with the control system: since the pumping station is of necessity on low-lying terrain, flooding is a definite threat and so the electrical gear needs to be well above ground level. The entire pumping system is usually set up in a small concrete-block building, with an emergency diesel backup generator to make sure that the sewage keeps flowing even if the electric grid goes down. In some residential areas, pumphouses are camouflaged as houses, complete with shuttered windows that "open" into a brick wall.

* Manholes provide access to the sewer system from the streets, though not all manholes are for the sewer system -- others are for water mains, gas pipes, or electrical or communications lines. Manhole covers for sewer systems tend to feature a number of vents, since the decomposition of sewage tends to produce flammable methane gas and it's not safe to let it build up.

Once upon a time, sewer system workers would go down the manholes to clean out the sewer lines using brushes on long rods, but these days it's generally done by a remote-control robot that can roll through the sewers, guided by a TV camera, and well-designed sewers rarely need cleaning anyway. The spacing of manholes is about 90 to 120 meters (300 to 400 feet) on straight runs, with additional manholes where the lines change direction or slope.

* The ultimate destination for the sewage is the sewage treatment plant, though in recent times the preferred name for such a facility is a "waste water treatment plant", with the latest label being "water reclamation plant". It's one of the most sophisticated elements of the entire water reclamation system.

The sewage first flows through a trash rack to get rid of large objects in the stream. Some plants use a "comminutor" instead, which grinds the large objects into tiny bits. The sewage still contains grit and other particulate solids that would jam plant machinery, so it is fed through a "grit chamber" that sorts out the particulate solids and leaves most of the suspended organic matter behind. One way this is done is to gently agitate the sewage with a stream of bubbles injected in the bottom of the tank; another method is to use a long sloping flume that reduces the flow rate enough to allow the grit to settle out while leaving the organic matter in the flow. The grit is collected and then disposed of; that can be tricky; while the grit itself is mostly just sand and dirt, it still contains a load of organic "putrescible matter" and can't be dumped into a landfill "as is".

Preliminary filtering accomplished, the sewage is fed into settling basins to lie stagnant. Light contaminants rise to the surface as "scum" and are removed by a skimmer; heavy contaminants sink to the bottom as "sludge", to be removed by a rake or conveyor belts. The settling process takes a few hours. The settling tanks are the biggest component of the plant, with the smallest plants having two and big plants having dozens. There's a certain "diseconomy of scale" in settling tanks, since the operating staff needs to be able to shut one down without slowing down sewage processing, which implies a number of small settling tanks instead of a few large ones; sewage comes in steadily whether the plant is working or not. Older settling tanks tend to be circular, with water welling up into the center and driving the materials to the edge, but rectangular tanks have become more popular since they are more space-efficient and cheaper to build -- two rectangular tanks can share a wall.

The settling process is called "primary treatment" and there was a time when could be judged to be enough, but now the sewage goes through another level of "secondary treatment". There are two approaches to secondary treatment: "trickling filters" and "activated sludge".

A trickling filter looks like a circular open-topped basin up to about 3 meters (10 feet) deep, filled with coarse broken stone and topped by a rotating sprinkler system consisting of four rotating arms fed by a central pipe. The sprinkler system sprays sewage on the stone, with the fluid trickling down over the stone to drains at the bottom of the basin. The stone is covered with a "slime" mostly made up of bacteria, with some algae, protozoa, fungi, and even worms and insects thrown in. The slime feeds off the contaminants in the sewage and cleans them out.

The activated sludge process also takes a biological remediation approach, but instead of a basin full of crushed stone it uses a sludge in a vat, known as a "reactor". The sludge is aerated to keep it alive, using either a mechanical aerator system that churns it up or a bubble aerator system that drives up bubbles from the bottom of the rack. Either scheme requires a fair amount of electric power.

The reactor is split into several cells or stages using concrete partitions, each with a different "ecosystem" to deal with specific classes of contaminants. Once through the reactor, the treated sewage is fed into another settling basin where the sludge can settle out, to then be collected and removed. The sewage may then be run through an activated-sand filter like that used in a drinking-water filtration plant. Some of the sludge collected has to be fed back into the reactor to keep the ecology going.

The effluent now looks clean, but it's still not healthy, being loaded with micro-organisms. The last stage before releasing the effluent involves disinfection with chlorine or chlorine-based compounds. As mentioned earlier, chlorine is environmentally troublesome and there is interest in alternatives, for example ultraviolet lamps to kill the micro-organisms.

With the effluent discharged, there remains the problem of what to do with the sludge. The answer is to "digest" it, using a closed and heated tank that promotes the grown of "anaerobic" bacteria, which live without oxygen. These bacteria produce carbon dioxide and methane gas that vaporize out of the sludge, as well as heavy solids that settle to the bottom of the tank. The gas is collected using a pipe at the top of the tank. The methane may be flared to eliminate it, though sometimes it is used to heat the digester or provide power to other plant systems. The deposited sludge on the bottom of the tank is dried, sometimes using a centrifuge to help squeeze out the water, and then spread out on drying beds. The sludge can be used as fertilizer for grass or other nonedible plants, but not food crops, since it would provide a path for "sewage to food" pathogens such as cholera.

* The sewer system also must carry away rain water, and in fact in the days when sewage wasn't treated, the sewage and "storm drain" systems were one and the same. In fact, that's not a big problem even today in places where it generally doesn't rain much or often, since the mixed sewage and rain water can all go through the sewage treatment plant. However, in case of a downpour, the sewage treatment plant will be overloaded, and so a secondary network of outlet pipes are arranged in the primary network, with the inlets to the secondary network set so high that normally nothing flows through them. When the fluid level in the primary network gets too high, it then flows through the secondary network, which shunts it directly off to a local river. That means dumping raw sewage in the river at such times, which is not ideal, but at least the sewage is also necessarily highly diluted when it flows out of the secondary system.

Up-to-date waste-water systems have entirely separate sewage and storm drain networks, but it's not practical to tear up the old combined networks and replace them, so they persist in the core areas of a large number of US cities. A dedicated storm drain system uses wide-diameter pipes to handle the high flow rates seen in floods, though the pipes don't have to be buried deeply since they don't need to connect to building basements.

Storm drain systems used to have catch basins to collect trash that might otherwise clog the pipelines, with the catch basins cleaned out by work crews every now and then. However, more modern storm drain systems feature heavily-sloped inlets that speed the rain water on its way. Storm drain systems were once designed to draw off rain water as fast as possible, but that could create problems when the huge, dirty surge was dumped in a local river or lake in a short period of time. Modern storm drain systems are more subtly designed, with ditches and ponds where the water can accumulate and then drain away relatively slowly. Modern zoning regulations tend to limit the "impervious area" of land plots -- the place occupied by buildings and parking lots where rain won't soak into the soil -- to keep the plot from simply dumping all of its rain load into the storm drain system. [END OF SET 2]



* GIMMICKS & GADGETS: I was looking through a news briefs page in AVIATION WEEK when I spotted one of the more interesting gadgets I've seen in a while. Boeing, working through partners in Taiwan, is converting a few old 747 jetliners into "Large Cargo Freighters (LCFs)", which will feature a blimplike fuselage intended to carry wings and other outsize cargo for the Boeing 787 Dreamliner.

The LCF was interesting, but what more got my attention was a "Cargo Loader" vehicle built by TLD of Sherbrooke, Quebec, to support the LCF. Cargo loaders are nothing new, consisting usually of trailers or self-propelled vehicles carrying a platform that can be jacked up or down for aircraft freight handling. The TLD cargo loader, however, is on the big side, resembling a bridge with a driver's cab on the forward right corner and fitted with a heavy-duty multi-axle truck chassis.

The TLD Cargo Loader is 36 meters (118 feet 1 inch) long, 8.38 meters (27 feet 6 inches) wide, has a low position of 1.78 meters (5 foot 10 inches), and a high position of 10 meters (33 feet 1 inch). It has a weight of 100 tonnes (220,000 pounds), can carry a load of 68 tonnes (150,000 pounds), and has a top speed of 16 KPH (10 MPH). Boeing is ordering six of them, with one each to go to the various airport hubs linking Boeing with the company's international network of suppliers.

What is interesting about the Cargo Loader is the thought that there is somebody out there making a living by building such a specialized piece of machinery, and actually has the expertise on hand to do it. Exactly how does an engineer become an expert in the design of aircraft cargo-loading machinery? It would seem like the industrial community would be on the small side.

* BUSINESS WEEK reports on a new gimmick from Japan that somehow seems distinctly Japanese: a DoCoMo picture phone that has an alcohol breathanalyzer built into it. It sounds like a bizarre idea, but it's targeted at bus, taxi, and trucking operations who want to make sure their drivers are sober. The management can call a driver and ask him to breathe into a tube fitted to the cellphone, with the picture capability ensuring that he actually does it instead of trying to use a ringer.

* According to an article from TECHNOLOGYREVIEW.com, a Massachusetts Institute of Technology (MIT) researcher named Matthew Orosz is working on a solar electric power system for developing-world nations that used old car parts and plumbing supplies. This solar power system is built around a parabolic reflector with an area of 15 square meters (18 square yards) and focused on a pipe full of motor oil. The hot motor oil is passed into a heat exchanger where it vaporizes a working fluid to drive a turbine, which then drives an automotive alternator to charge a battery. The oil is then water-cooled, producing hot water in the process. The overall cost is half that of a photovoltaic system, and it can be built with local materials and expertise.



* TEXAS WIND POWER: It is a Texas tradition to be the biggest and best at everything, and make sure everyone knows about it. According to THE ECONOMIST ("Blowing Strong", 1 July 2006), in mid-2006 Texas could claim almost 2.4 gigawatts of wind power generation capacity, placing the state slightly ahead of California, which has a bit over 2.3 gigawatts of capacity. Together the two states generate about half the wind power produced in the USA. For the moment, the Texan wind farms are concentrated in West Texas and the blustery Panhandle, but new offshore turbine farms are now being built in the Gulf of Mexico, where the wind is more constant and the population centers are nearby -- though hurricanes might be a problem.

The overall power contribution of wind to Texas is minor at present, but with Texas oil and gas becoming scarcer, and with a 1.8 cent per kilowatt-hour Federal tax subsidy, wind looks good on the bottom line. Growth has been limited by the inability to build turbines fast enough, and even more so by the difficulty of expanding the power grid fast enough to keep up with new capacity. Texas is a very big place, meaning the power lines have to run long distances, and to complicate matters, the Panhandle is on a different segment of the continental power grid than the rest of the state.

Texas state government is working hard to promote wind power, claiming that Texas has less red tape than the competition (that is, California). One interesting feature of Texas state government is that when President Sam Houston brought the Lone Star Republic into the Federal Union, he insisted on total state control over coastal waters, and got it. That means that the Federal government has not much over what the state can do offshore, simplifying development projects. There is also very little public "not in my back-yard" resistance to wind power in Texas, the state land commissioner, Jerry Patterson, describing the local attitude towards the controversies elsewhere with: "People here just kind of scratch their head and say: What's the problem? Get a grip." The military has raised concerns over Midwest wind-farm projects that might interfere with radar, but that hasn't happened in Texas.

There is still some contention over the wind turbines nailing migratory birds. Patterson admits that "there are going to be some seagulls popped" but adds after "after several generations we'll have smarter birds." This sort of unarguable but cavalier evolutionary thinking might suggest to outsiders the classic Texan mindset at work, but in reality the turbines are being given paint jobs to make them easier for birds to see at night, and the plan is to shut them down for maintenance in the spring and fall during the peak bird migrations. Since peak usage is in summer, when the air conditioners are humming away, the seasonal outages are not much problem.

wind power

Turbine technology for Texas wind farms is now being imported from Europe, but Texans are inclined to think that wind turbines aren't rocket science and so they might as well make the turbines themselves. The state government is looking around the business community to see who might be interested in getting into building wind turbines. Texas is not only windy, it's sunny too, and if Texans become the big shots of US wind power, Texan solar power might not be too far behind.



* MEASURING THE EXTREMES: As discussed by an article in AAAS SCIENCE ("Tipping The Scales -- Just Barely" by Robert F. Service, 5 May 2006), it has long been possible to weigh atoms, using mass spectroscopy, which involves ionizing atoms and seeing how much they are deflected after being shot through a magnetic field. Now researchers are trying to weigh atoms using a much more direct method -- nanosized mechanical scales. A team under physicist Michael Rourkes at the California Institute of Technology (Caltech) and his ex-student and colleague Kamil Ekinci of Boston University has managed to build such a system to measure a mass of 30 xenon atoms, with a weight of 7E-21 grams -- 7 zeptograms. In two years, the Caltech group plans to be able to weigh a single hydrogen atom, at 1.66E-24 grams -- 1.66 yoctograms.

Other research teams are working towards similar ends, with some believing that even single protons may be weighed in a few years. The major motivation in the work is to develop a mass spectrometer for nanosystems that can not only operate on tiny samples -- a classic mass spectrometer requires a large sample -- but can also measure the weight of neutral atoms, not just ions.

The race began in 2003, when researchers at the US Oak Ridge National Laboratory in Tennessee announced they had weighed organic compounds with a weight of 5.5E-15 grams -- 5.5 femtograms. A Cornell University team announced a scale operating in the range of 1E-18 grams -- an attogram -- in 2004, using the device to weigh single cells. The Rourkes-Ekinci device is now at the leading edge.

Most of these nano-sized scales involve tiny "beams" of silicon or other material suspended over a channel, with a beam suspended at one or both ends. A beam is oscillated and the frequency of oscillation measured. When a tiny spec of material falls on the beam, the frequency of oscillation changes, allowing the mass to be measured. The Rourkes-Ekinci scale involves bridges of silicon carbide in a vacuum chamber, with electric current passed through the bridges under the influence of a magnetic field, causing them to vibrate. Xenon atoms were then sprayed into the vacuum chamber through a port.

In four years, the research team has improved sensitivity a thousandfold, but they have to boost sensitivity a thousand times more to reach their goals. Other research teams are using slightly different approaches. Not only does sensitivity need to be improved, but operating a nanoscale in a vacuum is not necessarily practical, since the biomolecules that are high priority targets are often found in liquid solutions. Some researchers are experimenting with selective coatings that will attract target molecules and reject the rest. Research continues.



* THE RISE & FALL OF THE SLIDE RULE (1): As discussed in an article from SCIENTIFIC AMERICAN ("When Slide Rules Ruled" by Cliff Stoll, May 2006), there was a time in living memory when calculators were expensive, bulky mechanical devices, not something that could be put in a pocket. In those days, the standard "portable calculator" was the "slide rule", in which calculations were performed by moving two marked rulers against each other. The technology was so established that in the 1950s, science-fiction writers had astronauts flying to the planets and performing calculations with a "slipstick", as it was called.

slide rule

The underlying concept of the slide rule goes back to 1614, when a Scots scholar named John Napier invented logarithms. Many of us struggled with logarithms in school, but the idea is basically simple. A logarithm or "log" is no more than an exponent of a number. For example:

   10^2  =  10 * 10  = 100
   10^4  =  10 * 10 * 10 * 10 = 10,000
   10^8  =  10 * 10 * 10 * 10 * 10 * 10 * 10 * 10  = 100,000,000

In this case, the log of 100 is 2, the log of 10,000 is 4, and the log of 100,000,000 is 8. Logs have a particularly interesting feature. Suppose we perform the multiplication:

   100 * 10,000  =  1,000,000

This is the same as:

( 10 * 10 ) * ( 10 * 10 * 10 * 10 ) = 10 * 10 * 10 * 10 * 10 * 10

-- or:

   10^2 * 10^4  =  10^6

What this suggests that two numbers (100 and 10,000 in this case) can be multiplied just by taking their logs (2 and 4), adding them to get the log of the result (6), and then finding the "antilog", or value that corresponds to that log (1,000,000). Multiplication is reduced to addition.

Of course, just being able to multiply straight powers of 10 wouldn't be much good, but the notion of logs can easily be extended. Since any number multiplied by 1 is still that number, then "log 0" must correspond to an antilog of 1:

   10^0 * 10^3  =  10^3
   1 * 1,000  =  1,000

Following from that, negative logs can be defined as reciprocals:

   10^-2 * 10^2  = 10^0
   (1/100) * 100  =  1

Roots can be defined as fractional logs:

   10^(1/2) * 10^(1/2)  =  10^1
   SQRT(10) * SQRT(10)  =  10

-- or in other words, a log of 1/2 is a square root, a log of 1/3 is a cube root, and so on. Ultimately, any number can be expressed as a log, and two numbers can be multiplied by finding their logs, adding them, and then finding the antilog of that sum. Similarly, two numbers can be divided by finding their logs, subtracting one from another, and then obtaining the antilog of the result.

It should be noted that these examples have used 10 as a "base" of logarithms. 10 is a common base, but any other consistent value could used as well, with the most popular alternate base being "e", a nonending number with a value of 2.718281828 ... Of course, multiplication and division using logs demands that the logs be from a common base, in practice generally either 10 or "e", but not a mix of the two.

In any case, Napier's work led to tables of logs that greatly simplified calculations and were a great boost to the emerging scientific revolution. In 1620, a London mathematician named Edmund Gunter came up with a simple tool to help scholars quickly find approximate logs without having to look over tables, the tool being no more than a ruler that had log values evenly spaced on one half and their antilogs listed on the other half:

    0         1         2         3     log
    |         |         |         |
    |         |         |         |
    1         10       100       1000   antilog

In 1622, an Anglican minister named William Oughtred who was a math hobbyist put two of these scales together and found they could be used to multiply and divide. If the notion of logs is understood, it's not hard to see how this was done. Consider creating a simple adding machine by putting together two scales, labeled "A" and "B" with evenly-space numbering:

   A  0     1     2     3     4     5
      |     |     |     |     |     |
      |     |     |     |     |     |
   B  0     1     2     3     4     5

Then, to add 2 and 3, just move the B scale up to the 2 on the A scale, and read off the value on the A scale corresponding to 3 on the B scale, which of course turns out to be 5:

   A  0     1    <2>    3     4    <5>
      |     |     |     |     |     |
                  |     |     |     |     |     |
               B  0     1     2    <3>    4     5

Subtracting 3 from 5 would be the same operation read in reverse, yielding 2. Since multiplication or division can be performed by addition or subtraction of logs, then these operations could be performed essentially as above using two log-based scales:

   A  1         10       100       1000
      |         |         |         |
      |         |         |         |
   B  1         10       100       1000

Multiplying 10 times 100 gives 1,000 as shown below:

   A  1        <10>      100      <1000>
      |         |         |         |
                |         |         |         |
             B  1         10      <100>     10000

Dividing 1,000 by 100 would be the same operation read in reverse, yielding 10. Oughtred had invented the slide rule. A few years later, he had the bright idea of curving the two scales around in a circle and created the circular slide rule. Oughtred didn't bother to promote his idea, but he was still outraged when one of his students, Richard Delamain, published the concept of the circular slide rule and claimed it as his own. There followed a lifelong "intellectual property" quarrel which, as too often happens with such things, did neither of them any good. Oughtred finally concluded: "This scandall hath wrought me much prejudice and disadvantage." [TO BE CONTINUED]



* INFRASTRUCTURE -- WATERWORKS (5): A city water filtration plant is usually sited someplace out of the way, and so for many people the most visible element of the water system is the system of municipal water towers.

The water towers provide a local store of water for distribution, and also pressurize the water system. Without the towers, water would have to be pumped directly from the filtration plant through the entire network, which would demand very big and power-hungry pumps. The water tank system uses a set of small pumps that can run all night to lift water into the elevated tank for use during the day. The height of the water, or "head", provides the pressure for the end users.

Some of the very oldest water tanks that can be found in the USA are built like big wooden barrels, with vertical staves held together by steel bands -- the number of bands increasing towards the bottom as the pressure increases -- and capped with a shallow conical roof. They were usually placed on top of buildings to obtain head. The logical next step was to build much the same design out of bolted or riveted steel, perched on a platform supported by a framework of steel girders.

In the 1930s, the design of water towers began to evolve to more elegant forms, first by designing the base of the tank, where the pressure is greatest, with the strong half-sphere, using welding instead of riveting or bolting, and using tubular supports. It was not much of a jump to then make the entire tank a spheroid or ellipsoid. These are perfectly workable designs and are still being built, with capacities ranging from 568,000 liters to 11,200,000 liters (150,000 to 3,000,000 US gallons).

The evolution of this form led to the "monopod" water tower, in which the tank is spherical or ellipsoid but supported by a single heavy column, making it look something like a large mushroom. The first was built in Longmont, Colorado [just south down the road from me] in 1939, but the style didn't get popular until the 1950s. There's an inclination to give them fancy paint jobs, for example like a golf ball on a tee. The pedestal is mostly empty, with a "riser pipe" inside for pumping up the water and a smaller overflow pipe to keep the tank from being ruptured if something goes wrong and it's overpumped. One of the advantages of the monopod design is that the ladder up to the tank is inside the pedestal, making it more difficult for graffiti writers to deface the tank. There's a saying: "You know you're from a small town when you've gone up on a water tank with a can of spray paint to defend your girlfriend's honor."

monopod water tower

Big, high-capacity water towers tend to feature tanks that are wide and flattened, since if they were narrow and tall, they would provide too much pressure when they were full and too little when they were near empty. A big tower may have an ellipsoid tank with a fat pedestal, plus a ring of tubular supports around the edge. Another approach to a big tank is to build it as a flat drum, with a wide pedestal, giving something of an appearance of a huge fat nail pounded into the earth. Some small towns will have narrow but tall water tanks that look like something out of an oil refinery, but they're just trying to obtain a reasonable head for a relatively small tank. Tanks are usually emptied out about once a year for cleaning. The cleanup is performed using a disinfecting spray of chlorine or possibly ammonia.

* Laying out the water distribution system served by the tanks is a tricky exercise. In a small town, there may be one main line in the distribution center that terminates at the filtration plant reservoir at one end and at a water tank at the other. During the night, the tank is pumped up from the reservoir, and during the day the main is fed from both ends.

Optimum pressure in the water system is usually between 2 and 2.7 bars (30 to 40 PSI). The minimum acceptable pressure is usually considered to be 1.4 bars (20 PSI), which corresponds to a head of 14 meters (46 feet). The maximum pressure is usually considered as 4 bars (60 PSI), since that's when plumbing fixtures start to leak. Maintaining relatively uniform water pressure is troublesome in hilly areas. The solution is to divide the water system into "pressure zones", with the zones linked through pressure-regulating valves.

Most of the components of the water distribution system are underground to protect them from damage, particularly by freezing. In southern US states, the pipes are usually about a meter underground, going to about two meters (six feet) in northern states and about four meters in Alaska. Water mains still break. This can result in fearsome craters in roadways, though the popular notion of a pipe spontaneously bursting open isn't usually what happens: a pipe springs a slow leak that gradually undermines the supporting earth around a pipe, with the leak growing until the pipe has no support and breaks.

It's easier to fix the pipe if the leak's spotted before it becomes disastrous. Water system workers can be tipped off to an emerging leak when an arm of the distribution system seems to be drawing more water than it should, particularly in the dark hours of the night when water demand is otherwise lowest. The place where the leak occurs may be marked by unusually green vegetation. When the pipeline runs under open ground, workers may pound long spikes into the earth to hunt for soft, wet soil, or may uses microphones to listen for leaking water.

Valves are installed at junctions in the water system to isolate breaks. The valves are expensive and a maintenance headache, so there is an inclination to minimize their number. At a tee intersection, only two of the three arms have valves, and at a cross intersection, only three of the four arms have valves.

* A municipal water system also needs to support fire-fighting. This is not a secondary issue, either. Fire-fighting needs more pressure than household water systems, with the water system including booster pumps to provide more pressure in an emergency. New York City had an entirely separate high-pressure water distribution system for fire-fighting up until 1957, when pumper trucks rendered it obsolete.

The typical fire hydrant or "fireplug" is called a "dry barrel" hydrant, which means the valve to the hydrant is well underground, to keep the hydrant from freezing and preventing a gusher if somebody drives into a hydrant and breaks it. That always results in a fountain of water on TV shows, but it doesn't happen much in real life: it's the sort of thing that people would have fixed sooner or later, and actually did so a long time ago.

A typical US water hydrant has a ten centimeter (4 inch) outlet for the big "suction hose" of a pumper truck, and two six centimeter (2.5 inch) outlets for fire hoses. Hydrants may be color-coded to indicate flow capacity, for example green for high capacity, orange for medium capacity, and red for low capacity. A number of markers may be installed on or near fire hydrants to help locate them -- for example, in snowy regions poles with pennants may be planted next to them. Large buildings often also have ports for fire hoses in their walls, not only to provide water, but to allow pumper trucks to drive water through the building sprinkler system. [TO BE CONTINUED]



* SERVER FARMS: During my recent road trip I took a detour on the two-lane highways of the agricultural areas of central Washington in the region of Grand Coulee Dam. I hadn't been along that route in decades and it seemed like so little had changed; but I wondered in the back of my mind if that wasn't a superficial impression.

According to an article in BUSINESS WEEK ("Servers As High As An Elephant's Eye" by Peter Burrows, 12 June 2006), it was. The article detailed how the farmtown of Quincy, Washington has diversified into high-tech. Lured by the cheap hydropower in the region, running to eight times cheaper than the rates in Silicon Valley or Manhattan, both Microsoft and Yahoo! are now planning to build "server farms" -- essentially warehouses full of computer servers handling Internet traffic -- in Quincy. Local property prices have skyrocketed.

The infrastructure that maintains the Internet tends to be taken for granted, but the reality is that, for the big-time players, providing Web services isn't a case of setting up a server in a back room. It means providing a building full of servers, with the building protected by heavy-duty air-conditioning and backup power systems -- server farm operators say power goes down much more often than people realize. A server farm is not cheap, with the cost per unit of floor area about five times that of office space, and the power requirements mean that operating costs are high. It has proven difficult to build server farms fast enough to keep up with demand, and companies have felt the pinch.

Microsoft already runs server farms that draw the total power equivalent of 100,000 homes, but other companies don't have pockets as deep, and are finding the need to shell out the money painful. Manufacturers of servers and datacom equipment, in contrast, are enjoying current circumstances, and are working on new gear that draws less power. Towns like Quincy are happy, too: once backwaters, they are now becoming hubs to the world.

* AUTONOMOUS PROBES: According to an article from late May on BBC WORLD Online ("Mars Robots To Get Smart Upgrade" by Jonathan Amos), the highly successful US National Aviation & Space Administration (NASA) Spirit and Opportunity rovers on Mars have been given an upgrade. Software has been downloaded to allow them to spot clouds and dust devils in their imagery, then pass the relevant images on to Earth. Previously, researchers had to wade through streams of imagery on the chance that there might be such phenomenon there.

The agency believes this greater autonomy is the way of the future. The NASA Mars Odyssey Orbiter, which has been mapping the Red Planet since 2001, will get new software later this year to make it more alert for temperature anomalies, rapid changes in the polar icecap, emerging dust storms, and the formation of clouds. If such phenomena appear, the orbiter will break from its assigned duties and observe them without asking Earth first. This will allow the spacecraft to pick up transient activities that might otherwise be missed.

The technology was originally developed for the NASA Earth Observer 1 (EO-1) satellite, which has been performing autonomous observations since 2003. For example, it was able to spot a 2004 eruption from Mount Erebus in Antarctica and automatically take targeted readings. Along with greater responsiveness, the autonomy also helped reduce the staffing for mission controllers, since the spacecraft could take over some of the work itself.

NASA is considering a range of deep-space missions, such as a blimp that could traverse the skies of Saturn's moon Titan. Since the place is so far away and communications delays are so great, there would be no way for the blimp to navigate under control from Earth. The blimp would simply receive general commands from its control center -- as well as software downloads to make it smarter.



* GAMES-A-GOGO: According to an article in BUSINESS WEEK ("Tiny Games For A Giant Market" by Cliff Edwards, BUSINESS WEEK, 3 July 2006), games for cellphones are becoming one of the latest buzzes in the tech world. Bored on your commute and unable to concentrate on anything useful? Play a game to kill the time.

The buzz is over the potential. There could be 2 billion phones capable of running reasonably sophisticated games by 2010, with the market for cellphone games even outstripping the market for ringtones. Cellphone makers like Motorola and Nokia are teaming up with chipmakers like Texas Instruments and Nvidia to build cellphones with big color displays and 3D graphics engines optimized for gameplay. Venture capitalists are funding startups with plans to build "casual games".

Of course, putting games on cellphones suggests a certain technological leverage, with multiplayer cellphone games incorporating text messaging and voice communications. Disney Internet is working on such technologies, and Nokia has a Snap mobile system that supports wide-area multiplayer gaming. Other companies have their own ideas: gamesmaker Electronic Arts wants to make "episodic" games that run like a TV series, and Microsoft is working on an "Xbox Live" system that will allow users to get into the game on either their cellphone or their Xbox home console.

Some critics think cellphone gaming is an illusion. So far, it has certainly been a nonstarter, with only about 4% of cellphone users actually buying a game and downloading it. A $7 USD game may sound cheap, but right now the games are only played a few times and then deleted, making $7 USD seem like not much of a bargain. Although gaming subscription services have been set up, few seem to think they provide a value proportionate to the monthly fee. The only really big "hits", if they can be called that, for the cellphone gaming market so far have been ports of classics like Pac-Man and Tetris.

Flashier games mean higher development costs, and the cellphone market suffers from a lack of standardization: getting good market coverage means ports to a number of different brands of cellphones, increasing costs and complicating logistics. In addition, the wireless carriers control the cellphone industry at the end-user level, and the carriers have been insisting on their cut from the games, choking the economics still further. Carriers have also been slow to promote gaming. The field may stall on its own internal barriers, but the potential payoff is keeping the industrial interest high for the time being.



* CANNY CHAVEZ: Americans tend to find Venezuelan President Hugo Chavez irritating, which complicates forming an objective judgement of the man. An article in THE ATLANTIC ("The Talented Mr. Chavez" by Franklin Foer, May 2006) paints a picture of Chavez that shows him to be shrewd and calculated, if not necessarily good news for Venezuela.

Focus, to begin with, on Chavez at a public rally, wearing a sombrero. He works the crowd, he sings, he tells jokes -- and then gets on to the meat of his presentation, telling the people about Venezuela's plans and taking swipes at Venezuela's enemies. It was a real crowd-pleaser. His opponents find such performances buffoonish, and in fact he deliberately clowns around on occasion. An old friend and sometimes rival, Francisco Arias Cardenas, calls him a "superb strategist" and points out that his deliberate buffoonery is a ploy to make his enemies underestimate him -- for example, pretending to confuse a carrot with a beet on a TV show, with the end result that the critics carp on his foolishness for a week, instead of paying attention to what else he was doing during that time.

Chavez draws much of his inspiration from the great South American revolutionary Simon Bolivar. During the Chavez Venezuelan presidential campaign in 1998, a chair was always left empty at meetings, reserved for the "liberator", Bolivar himself. Chavez wants to be a liberator for Latin America as well, but this time around the colonial power is the USA, not Spain. He promotes a mix of anti-Americanism, Bolivarian assertiveness, and statist socialism that he calls "Chavismo".

Chavez calls US President George W. Bush "Mister Danger", or simply "The Asshole", and describes US Secretary of State Condi Rice as a sexually-frustrated illiterate. Chavez has yanked all Venezuelan assets from US banks, makes cozy with adversaries of the US such as Iran, and at least puts on a show of preparing Venezuela for a US invasion -- it's theatrics, though no doubt he remembers what the Americans did to Panamanian dictator Manuel Noriega, who is still rotting in prison in the USA. The snubs to the USA get a good reception from many in Latin America, as well as the international anti-American Left; exiled Leftists have found Caracas a welcoming new home, and Chavez has cultivated contacts with the Left in other countries.

Bolivar put together a short-lived South American "super-nation" named Gran Colombia, and Chavez would like to do something along the same lines. Funded by Venezuela oil wealth, he has been exporting his ideas over the continent, aided by the Venezuela-based Telesur satellite TV network, Chavez's answer to CNN. Chavez has the money, has the moxie, and the Americans don't have any good idea of how to deal with him. He may well go far.

* In the 1960s, Venezuela was a progressive liberal-democratic state, with an educated populace that enjoyed considerable civil liberties. However, corruption began to rot the social order, and by the late 1980s there was widespread dissatisfaction with the way things were being run.

Chavez was a country boy from the backwoods who came to the big city in the 1970s to become a pro baseball player. He ended up in the military instead, stepping up steadily through the ranks, but becoming disillusioned as he did so, later citing as the critical event the night he lay awake listening to captured Leftist guerrillas being worked over with towel-wrapped baseball bats. He began plotting to stage a coup and spent ten years working on that goal.

The scheme was put into motion on the night of 3 February 1992, with support of about 10% of the military. Nothing went right, and when Chavez found himself surrounded, his colleagues lying dead around him, he gave himself up. State TV repeatedly ran a video of him announcing that the coup had failed, thanking his colleagues, and taking responsibility. The reason for running the video was to damp out the uprising immediately and discourage future coups, but the authorities failed to see how Chavez had used the opportunity to deliver a neat bit of oratory that put him in a heroic light.

He in fact became a national hero, with his trademark red beret becoming a fashion item in Caracas slums. His popularity was such that he was freed from prison in 1993. The government didn't need to worry about Chavez launching another coup, since he'd had another revelation while in prison: he could take over using the ballot box.

* Chavez is a populist who honestly believes in helping the people, and all who know him see that he thrives on their praise. Under Chavismo, in 1999 he introduced a new constitution that appeals to the public, who can now recall a president by referendum and set up co-ops with state support. His critics point out how the new constitution enhances the power of the presidency by replacing a two-house legislature with a more easily managed one-house legislature, and eliminating congressional oversight of the military. Previously, Venezuelan presidents could only serve one consecutive term, but that rule has been changed, and he is now trying to change the rules further so he can serve three terms instead of two. It remains to be seen if he will try to set himself up as "president for life".

Chavez is no thuggish dictator like Noriega, and at present Venezuela does not look like a Castroite people's republic by any means, with plenty of private business in operation and people criticizing Chavez openly in cafes. However, the government is gradually extending its reach. In 2003 and 2004, petitions began to circulate for a recall referendum against Chavez, as guaranteed in the 1999 constitution. The names and national ID numbers of the petitioners then mysteriously appeared on a website associated with a Chavez supporter, and the government began to refuse passports, public contracts, and welfare to those who had signed -- though when a government minister made noises about firing employees who had signed, public outcry forced a retraction. Laws have been passed to allow the government to suspend media outlets that are "inflammatory", and the TV networks have become suitably cowed without the government actually taking further action. Chavez has stacked the courts with his people, and after an abortive 2002 coup he purged the military, firing untrustworthy officers and replacing them with his cronies.

To keep the poor happy, he has been showering oil money on them, bringing in Cuban doctors and a legion of teachers. Poor neighborhoods now have government-subsidized grocery stores, Internet access, and medical care. All the largess is praiseworthy in itself of course, but critics point out that it is a band-aid approach, more grandstanding than wise investment, saying that the public hospital system is growing creakier, and number of people under the poverty line has increased from 43% to 53% during Chavez's reign. The Chavez government is not the kind of finely-tuned machine that could change fundamentals. Hugo Chavez is a populist, not a technocratic bureaucrat, and his government rotates around him.

* As far as the war of words with the US goes, there is less there than meets the eye. Yes, Venezuelan oil does give Chavez leverage over the USA, but Venezuela is at least as tied to the US market in return. American refineries are needed to process high-sulfur Venezuelan crude, and the shipping infrastructure is set up to supply the USA. Finding an alternate market for Venezuelan crude would be a painful adjustment. Venezuela can also hardly cut the ground out from underneath the 14,000 CITGO stations the state oil monopoly owns in the USA.

Still, Chavez is sincere at the gut level in his anti-Americanism, and the message is popular through Latin America. There has been some disillusionment with free-market economic thinking in the region and the USA simply comes across as the defender of the disagreeable status quo, a perception not improved by occasional acts of American heavy-handedness on the international stage. Hugo Chavez gets an attentive audience when he goes to free-trade meetings only in order to blast and undermine them.

It is of course possible to argue, even persuasively, that free-market capitalism is oversold, but the Chavez solution seems dubious. Who benefits from centralization of political and economic power, and the dismantling of checks and balances on the authority of the leadership? It's not hard to see that the only real consideration involved is the convenience of the leadership, and the track record of overbearing statist governments in providing prosperity or personal liberties is not very good. However, given Venezuela's oil wealth, the Chavez regime may obtain a grip on power that will last a long time.



* THERE & BACK AGAIN (4): On Thursday of my trip to the Northwest, I got up early to make sure I missed Seattle rush hour-traffic and went back east over the mountains. On the way back, the plan was to get off Interstate 90 and take the two-lane highways up through the prairies to Grand Coulee Dam to get some shots.

I hadn't been through the farmlands of central Washington for a long time. They're flat, full of crops where irrigated, dotted with sagebrush where not. I went north through Ephrata, with my first stop at Dry Falls, the spectacular gouge in the earth where the massive Bretz floods of about 20,000 years ago -- named for the geologist who figured out how Dry Falls and other odd gouged-out features in the "scablands" as they are known came to exist -- ripped through the region. Once again, my wide angle camera came in handy.

Dry Falls

I did a loop up to Chief Joseph Dam and then back down to Grand Coulee Dam to get pix; although the Chief Joseph Dam is much less spectacular than Grand Coulee Dam, it was actually a fairly interesting photographic subject, since the dam's transformer gear is lined up in a convenient way for shooting. Grand Coulee Dam, at the time of its construction the world's biggest, is simply too huge to give much of a sense of detail, though the electric switchyard is photogenic for those fond of machinery.

The trip back to Spokane through the farmlands was dull: I swear that the little towns like Wilbur and Davenport don't look at all different from how they did forty years ago. It wasn't a long drive, and I had plenty of time to take care of some business when I got back to town.

* Although I missed out on some shots I wish I'd nailed, I more than made up for them by getting lucky elsewhere. Fairchild Air Force Base outside of Spokane operates KC-135 inflight refueling tankers. The base perimeter is so wide that it's impossible for me to get pictures of anything on the flight line, and since the sorties of the tankers are infrequent and unpredictable, trying to simply stand around in a store parking lot or whatever outside the perimeter to get shots of aircraft coming in and out wasn't practical.

However, as I was coming back from Grand Coulee I spotted a KC-135 coming in on its approach to Fairchild; I immediately pulled over into a supermarket parking lot and got out my camera. I was too late, but then it came back around three more times, giving me plenty of opportunity to catch it. I was wondering why the pilot was performing so many go-rounds, thinking at first that it was training, but there was a strong wind blowing as I was trying to get my shots and I suspect he was having problems with crosswinds.

My folks live in a gated community next to the Spokane river that has a number of small plots left half-wild for atmosphere. As a result, despite the fact that the community is near the center of town, there's plenty of pheasant, quail, raccoons, woodchucks, and other "urban fringe" wildlife around. On Monday evening I heard a ringnecked pheasant rooster crow and went out to find him; I did, but when I tried to get close enough to get a good shot with my camera, he started playing games with me, circling around cover and getting behind me. I was surprised how cagey he was, leading me in circles, apparently in an effort to draw me away from his nest and hen.

Giving up on this, I turned around to see a quail standing in front of me on the pavement. I tried to take a shot; the bird then began loudly vocalizing: "Ah-HOO-ha! Ah-HOO-ha!" -- and ran off into the bushes. Funny, I'd heard that call before, but I'd never linked it to quails: "You laughing at me, or what?"

On Friday evening I was packing and my Mum said the quail was wandering around in front of the house on the driveway. I grabbed my camera in faint hopes of getting a shot and went outside. It turned out it was sitting on one of the brick gateposts for the gate into the community. It seemed cautious of me but I could get within about ten feet of it, which was all the range I needed. I fired off a series of shots from different angles, two of which later turned out to be pro-quality. When I got closer it moved off down the fenceline, but it never seemed particularly fearful of me, as if he were as curious about me as I was of it.

Comical little beasts. I recall when I was running in Spokane many years ago I would occasionally see a momma quail running alongside the edge of the road with a row of chicks in train, like a set of windup toys on a string. The old Looney Toons crew did exactly one cartoon whose hero was a ditzy quail. It seems a bit surprising that more wasn't made of the character, since quails are so cartoonish in real life.

I heard the pheasant crow again and found him; he was prowling around in the shade and I couldn't get a clear shot. I knew better than to try to follow him, he'd lose me in the brush immediately. Nail him later; a pretty bird, a Chinese import, one of the few real success stories of species introduced into the USA, appreciated by both birders and hunters. I got a good shot of a woodchuck standing up on a path to check me out in compensation.

I was able to get other good shots on an opportunistic basis during the trip: pronghorn antelope in central Wyoming, a CENEX oil refinery in southern Montana, some nice aircraft at the Spokane airports, and so on. It's a bit surprising how many good photo subjects can be found if you're on the lookout for them and driving with a zoom camera on the other seat. Incidentally, most of the photos are in the photography archive on the website now if you want to check them out.

* Having scouted out the Seattle and central Washington area this trip, I figure I'll take a similar digressive trip the next time I go to Spokane. On the way out, drive to Idaho Falls, Idaho, to check out the zoo there; then spend the night there and do a fast tour of Grand Teton and Yellowstone before proceeding on to Spokane via Montana. On the way back, visit the zoo in Billings, Montana, then go on to Gillette, Wyoming to spend the night; in the morning visit Mount Rushmore, the Crazy Horse Memorial, and Devil's Tower -- they're all in a loop that looks like an hour or two's drive.

I've been to Devil's Tower before. I was disappointed. I didn't see an alien mothership. That's what I get for visiting during daylight hours. [END OF SERIES]



* INFRASTRUCTURE -- WATERWORKS (4): A few cities, like New York, have water supplies so clean that all that has to be done before delivery to end users is add a small dose of chlorine. Most other cities need to use a filtration plant to clean up the water first.

The filtration plant usually amounts to more than just a filtration system, since it provides a good site to establish the operational headquarters for the water department, where the technical staff spend their workdays and workers are dispatched to service the city water network. There may be garages, repair shops, and a water-quality testing lab. However, all this is built around the filtration system. Reservoir water is kept as sanitary as possible, but as it's delivered it's not fit to drink, full of silt and sediments, and more than likely bacteria that might be harmful.

The water from the main reservoir flows into a local reservoir at the plant, which can provide a few day's water supply in case the aqueduct is shut down for repairs. The water from the local reservoir is then passed through trash racks and screens to get rid of the gross contaminants, to then be fed into a "mixing basin". This is a small tank, maybe 3 meters (10 feet) deep, in which the water is mixed with chemicals and churned into a froth by an agitator, driven by an overhead motor. The chemical additive is mostly alum, a form of aluminum sulfate, but some iron compounds and traces of polymers may be included; the additive forces particulates to congeal into consolidated particles called "flocs".

After this exercise in "shake rattle and roll", the water is fed into a "settling basin", where the flocs continue to grow until they get too heavy to float and sink to the bottom. Settling basins may be circular -- with the water fed into the center and flowing out to a weir that runs around the perimeter -- or rectangular -- with the water flowing in one end and down to the other. In either case, the flow of water must be slow and smooth to prevent the flocs from breaking up.

Of course, the settled particulates have to be disposed of. In some cases the sludge is mucked up every few weeks or months, but these days it's generally collected as it accumulates. Circular basins have a rotating rake on the bottom that gently nudges the sediments into a central drain, while rectangular basins use a conveyor belt that carries them to scraper, to be scraped off into a hopper. The consolidated sediment is generally not hazardous, but it has no particular value either, and usually ends up as landfill.

Now comes the interesting stage, the filter bank. This used to be a bed of fine, clean sand, with the water flowing down through the sand and leaving solid impurities at the top of the bed. The surface of the bed would gradually accumulate filth and grow a layer of nasty slime that was known by a German term, "schmutzdecke (filth layer)" -- for some reason German seems to sound right for this sort of thing. The schmutzdecke had to be scraped off and replaced every few days.

Obviously this approach left something to be desired, and these days such "slow sand filters" have been replaced by "rapid sand filters". A typical rapid sand filter actually consists of three layers -- a thick layer of powdered coal on top, a smaller layer of fine sand, and then a bed of pebbles and gravel. The entire bed is a bit under two meters (about six feet) thick. Water is pumped down through it under pressure and the sandwich of materials efficiently draws out the contaminants.

Of course, the bed gets dirty very fast, and so it has to be cleaned. While the water is being filtered, some of it is set aside in a tank of its own, and about once a day this tank is fed back up through the bed. The "backwashing" process churns up the bed -- at some plants air is bubbled up through the bed as well to help -- and drives out the contaminants as waste water. Once the backwashing is done, the bed settles back down and re-assumes its original configuration: the heavy pebbles and gravel on the bottom, the sand in the middle, and the light powdered coal on top.

The final step before distribution is chlorination to kill off lingering micro-organisms. In large plants, chlorine is delivered as a liquid under pressure in steel cylinders or by tanker trucks. It must be remembered that the straight diatomic chlorine (Cl2) gas is toxic, having been used as a weapon early in World War I because it attacks the lungs, and so chlorine has to be handled carefully. Small plants may stock a relatively harmless chlorine compound, usually sodium hyperchlorite, and chemically produce the chlorine as needed. Either way, the chlorine is mixed with warm water to create a concentrated solution and then mixed with the output of the filter banks. Fluorine is added in a similar way, since traces of it help prevent tooth decay.

The water ends up in a holding tank, ready to be pumped out to end users. It is not used for at least 24 hours, to give the chlorine more time to disinfect the water. The holding tank is big enough to handle surges in demand.

Chlorination has been a bit controversial, but since the alternative is a contaminated water supply, it's been generally accepted. Regulatory agencies have been gradually tightening up standards for water supplies, which would seem to push more chlorination, but on the other hand chlorine can combine with organic molecules remaining in the water to create polluting chlorinated compounds whose levels are need to be controlled. The approach being investigated to get around this dilemma is to pump ozone -- the reactive O3 molecule -- through the water, though ozone is an urban air pollutant.

Of course, fluoridation of water supplies has been controversial since day one, though the resistance against it mostly lies on the fringe. Fans of the classic Cold War movie satire DR. STRANGELOVE will remember how Air Force General Jack D. Ripper ordered his bombers to attack the USSR because of "fluoridation of our water supplies".

Process control at a water filtration plant is generally performed in a gradual and cautious way. If the water gets too acidic, a small quantity of alkali may be added to compensate, with the staff waiting a half hour or so for the change to stabilize before doing anything else. Since the plant is so vital to the community, it is generally designed on redundant lines, with two of everything and backup electric generators to make sure it keeps on working no matter what happens. [TO BE CONTINUED]



* RUSSIA (BACK) TO THE MOON: During the 1960s, the Soviet Union engaged in a race with the USA to put men on the Moon. The Soviet manned Moon effort, hobbled by limited funding and bureaucratic rivalries, was a dismal failure. However, the USSR also conducted an energetic program of unmanned lunar exploration that was an outstanding success, featuring the first successful planetary soft-landing, rover, and sample-return missions. Following the end of the manned Moon race, the Soviets lost interest in lunar exploration of any sort, and the collapse of the USSR put space science missions in limbo for over a decade. Now, according to an article in AVIATION WEEK ("Russia's Lunar Return" by Craig Covault, 5 June 2006), the successor Russian state, buoyed by oil money, is planning a return to the Moon.

The mission, designated "Lunar-Glob", is now in initial development. It will involve a Moon orbiter that will drop a network of ten "high speed penetrators (HSPs)", two "penetrator-landers (PLs)", and a single soft lander" or "polar station (PS)" onto the Moon's surface. One of the PLs will be dropped on the old American Apollo 11 manned Moon landing site, while the other will be dropped on the Apollo 12 landing site. The PS, as its name implies, will set down on the Moon's south pole to look for water ice deposits.

The ten HSPs will each carry a seismometer and telemetry systems as a payload. They will be carried in a "cassette" that will be deployed from the orbiter as it approaches the Moon, with the cassette dropping the HSPs into two ring-shaped patterns in the Moon's Sea of Fertility. The two PLs will then be deployed from the orbiter; they will have a more sophisticated payload and will also have a retrorocket system to partly brake their descent, apparently to prevent damage to some of the instrument payloads.

Once the penetrators are deployed, the orbiter will go into polar lunar orbit, to then drop the PS soft-lander into a crater in the Moon's south polar region. The PS will land using a retrorocket / airbag system, and will carry a payload consisting of a mass spectrometer, neutron spectrometer, and seismograph. The orbiter will relay data from the thirteen landers; it is unclear if it will have any instrument payload of its own. Launch of Lunar-Glob is scheduled for 2012. The Russians are also planning a sample return flight to the Martian moon Phobos, to be launched in 2009.



* AFROPHONES: Although most of the news that comes out of Africa seems to be bad, some of it is upbeat. One positive item, as described in an article in IEEE SPECTRUM ("Africa Calling" by Victor W.A. Mbarika & Irene Mbarika, May 2006), is how Africans have taken to cellphones in a big way and made good use of them.

In fact, sub-Saharan Africa is the fastest growing cellphone market in the world, with 82 million subscribers (not even counting relatively sophisticated South Africa) as of the end of 2004. The cellphone fills a need for communications that can't be filled by national telecommunications monopolies in countries that almost always lack the funds to invest in infrastructure and are too often badly hobbled by corruption.

Wireless networks, in contrast, are being set up by commercial operations and don't require a massive investment in infrastructure. Though the headlines might not suggest it, Africa has become considerably more peaceful in the last ten years and outsiders are willing to invest in a growth market. Given the difficulties of doing business in Africa, wireless telecom firms have had to come up with clever business models to be able to make a profit selling to people whose median income is wretchedly low.

* The African cellphone revolution began in 1993, when the South African government granted national cellphone licenses to MTN South Africa LTD and Vodacom Group LTD. Both companies, which were partly owned by the government, quickly built up large customer bases, first in South Africa and then over much of the rest of the continent, by selling prepaid phone cards. Such a scheme was attractive to customers who couldn't afford a monthly phone bill, and didn't have postal addresses or checking accounts. People could pay as they went. The business model was hugely successful. In Uganda, over half the population has cellphone coverage, with 98% using prepaid cards.

The other factor in the success of cellphones has been cooperation with national telecom authorities. Knowing they don't have the resources to lay landlines, in many cases national telecom organizations have simply partnered with cellphone providers to get the people talking over the airwaves. There has been intense competition among cellphone providers to crack these national markets, leading to low prices for end users -- though likely a bit of palm-greasing as well in countries where such practices are normal.

Africa is rich in natural resources, but oil and diamonds have often proven counterproductive, leading to intensive corruption, outright warfare, and nothing trickling down to the people on the bottom of the pyramid. The cellphone revolution, however, does seem to be creating wealth up and down the ladder. It is profitable for the operators of course, but it is also profitable to the end users.

The economic life for African villagers is necessarily small-scale, but there are opportunities for the enterprising even at such a minimal level. Villages and city neighborhoods invariably have a "wireless phone kiosk", a shack where customers who can't afford a cellphone can rent one by the minute from someone who can. In Kenya, entrepreneurs don't even necessarily set up a shack, instead simply carrying a phone on a lanyard around the neck and strolling through a marketplace to find customers.

In Kenya, the going rate per minute is about 25 cents per minute for a local call and twice that for an international call. The rates are reasonable -- given the poverty of the customer base, they have to be since few have the money to pay much more -- but the business is profitable, earning up to $400 USD per month for the vendor.

Selling the prepaid cards is another profitable business. They're often sold in convenience stores, or by street vendors who may wander through city traffic jams to push their product. Yet another source of revenue is selling short messaging services to provide news, financial data, sports scores, and even horoscopes.

Complicating the business is the fact that in the rush to set up mobile phone systems, there was little pressure to insist that networks be interoperable, and so they generally aren't. That means that a kiosk owner, or businessman who needs to talk to a wide customer base, has to own several phones, one for each network in the region.

* Despite the difficulties, the introduction of the cellphone to Africa has proven a revolution. Like all revolutions, the details are messy: a cellphone makes it easier for a husband to keep in touch with a mistress without his wife knowing, and thieves have become particularly fond of stealing cellphones. However, if there were any doubts that communications is an engine of commerce, the increased opportunities for finding out about and making deals erases them. Open communications has also helped fight government corruption. In Senegal in 2000, a network of citizens armed with handheld radios and cellphones kept an eye on polling stations in a presidential election, making sure there was no cheating.

The final question is: can the boom be sustained? Although street businessmen can keep themselves and their families alive with a cellphone, they don't generally earn enough to expand their business to a higher level. Most of the telecommunications investment in Africa has been funded by foreign companies, meaning that the profits at the top of the pyramid don't end up in the pockets of Africans -- a process that some consider "neocolonialism". Despite all that, it's all but impossible to say that the cellphone hasn't been a big benefit to Africans. The continent still has many problems to fix, but at least the people are talking now.

* In related news, THE ECONOMIST reports ("Dial M For Mujahedin", 20 May 2006) that when the Taliban were evicted from their rule of Afghanistan, there were only about 20,000 working phones in the country. Thanks to cellphone technology, there are now about 1.3 million. As in Africa, cellphones are useful for business; in a country where contacts between the sexes are strictly controlled, they also offer a discreet way for young men and women to chat with each other. Even the Taliban has made use of them, fitting them to remote-detonation bombs.

A weak electric-power infrastructure in Afghanistan is a limiting factor, though that suggests the possibility of a brisk business in solar-power battery rechargers. Talk of improving communications to the outside world with fiber-optic links is also running into opposition from conservative government elements, who don't like the idea of young Afghans surfing the Web to find pornography, or worse, foreign ideas.



* OVERBLOWN IDENTITY THEFT? With the rash of reports of thieves stealing laptops and servers storing huge customer and user lists, there's a widespread impression that "identity theft" is out of control. The US Federal Trade Commission issued a report in 2003 that estimated ID theft losses at $48 billion USD a year. The theft in May of a laptop from the home of a US Veteran's Affairs (VA) staffer that contained a file listing data on 29 million active and former military personnel was a particular eye-opener.

According to a BUSINESS WEEK article ("ID Theft: More Hype Than Harm" by Dean Foust, 1 July 2006), the actual level of damage from ID theft is much smaller than it's been made out to be. In the aftermath of the major heists of customer lists, a US Federal Bureau of Investigation official said: "What we've seen has not been significant. Given the high profile, we would have expected to have seen more."

In hindsight at least, the fact that the ID heists haven't resulted in a wave of losses to the potential victims is not surprising. If thieves were specifically after such lists they would be prepared to exploit them, but if a thief just wanted to snatch a laptop, he might not have any idea of the significance of data he had stolen or have the connections to turn it into gold if he did. If he did understand what he had stolen, he might not be happy to have it -- stealing a laptop is a mundane crime, not one the authorities are going to invest major resources in solving, but stealing a list of 29 million military personnel and veterans is asking for a lot of trouble.

Even if the thieves were after the lists, prompt notifications to the users affected usually greatly limits the damage. For lists of online accounts, users can usually simply change their passwords. In other cases, the data wasn't in a very usable form -- the VA list was in a database format that would have been tricky to decipher. To be sure, nobody likes the idea of strangers being able to access their accounts, but a recent survey suggests that only one out of more than a thousand users whose accounts have been compromised actually suffers losses.

The archetypical ID theft crime is stealing credit-card numbers, but thanks to ever-increasing vigilance, losses from credit-card theft have been dropping steadily for years. In 1991, Visa lost 19 cents from theft for every $100 USD in credit card transactions; now that's down to 7 cents. The credit-card companies have developed sophisticated screening software that will notice unusual transactions and block them. This is why people occasionally find out that a credit-card transaction, particularly a large one, that varies from their usual purchasing habits is blocked, with other transactions also blocked for about a day.

The FTC's 2003 estimate of losses of $48 billion USD was obtained by calling 4,000 individuals, determining their rate of losses, and extrapolating to the entire US population. More careful recent surveys suggest the actual loss is more on the order of $3.2 billion USD -- not peanuts but an order of magnitude smaller than the FTC estimate. Estimates of bank losses run to $1.1 billion USD. The FTC survey did have one interesting data point that ends up being both reassuring and un-reassuring. While the usual idea of ID theft brings up a vision of organized gangs of hackers, about a quarter of those who told the FTC they'd been ripped off identified family, friends, and neighbors as the culprits. The scale of the crime was petty -- but it makes one wonder who can be trusted.



* THERE & BACK AGAIN (3): On the Wednesday component of my Northwest USA trip, I took a morning drive south from Federal Way to the flanks of Mount Ranier to visit Northwest Trek Nature Park. This is a wild-animal park in the forests, built on property donated by a local doctor some decades back, in which deer, buffalo -- OK, if you must "eschew the vernacular", bison -- caribou, bighorn sheep, mountain goats, moose, raccoons, and so on range free in the woods and glades, while large predators are kept in more confined enclosures. It was well worth the trip.

mountain goats

Visitors ride a double-length segmented tour bus to go through the park. Walking around inside the open area is not permitted, since buffalo have an inclination to gore and trample humans into the ground when irritated. I didn't spot the moose: they had a cow, but there had a been a big windstorm not long before and a falling tree had killed their bull, and they were awaiting a replacement.

The predators in the enclosures were fine sights, but I was dim enough to leave the instruction manual for my Coolpix 8800 camera at home. I had been relying on auto-focus, which uses an edge-detection scheme for focusing. That works fine for buildings, aircraft, and other machines, but it's a bit tricky to find any visible sharp edges on, say, a bobcat, particularly under low-contrast dark-forest conditions. I couldn't figure out how to get manual focus to work and lost some really great shots. It was one of the first things I figured out when I got back home. At least the procedure was tricky enough that I didn't feel embarrassed for not figuring it out on my own.

I was planning on visiting the Fort Lewis military museum whilst I was in the area, but to make a long obnoxious story short, I had to submit to a tiresome security check and it wasn't worth my bother. It was another irritation to have the base museum website encourage visitors when base security's attitude was: "Who the hell are you and what the hell do you want?" I did not find that attitude unreasonable in itself; it's just that the mixed message brought back memories of how the military operates. Reminds me a bit of an NCO I had who a slick Latino trooper memorably described to me as "a very funny sergeant -- he will shake your hand with one hand and hit you across the head with a hammer with the other."

Hey, I was just leaving, cowboy. However, although the military is not noted for its quick-wittedness, it does have a certain common sense, and it appears that there is a general push towards moving base museums offsite to facilities under civilian control and making everybody happy. Fairchild Air Force Base in Spokane shut down its museum, and all its materials are being used as the basis for a civilian air museum that a city group is trying to set up at the local airport. Whatever the case, that's the last time I try to go to a place where I get the nasty feeling I'll be subjected to a cavity search if I crack a smile.

I recovered from that fumble quickly -- the only real failure being not to cut my losses sooner -- heading up to Point Defiance Zoo & Aquarium in Tacoma. It's not the biggest zoo, but it is pretty and well laid out, and I got some first-class pix of a tiger, sea otters, and some other creatures. That finished off my preplanned agenda in the area, but on the way back out of town I got curious about the Tacoma Narrows suspension bridge and took a detour to get pictures of it.

The original Tacoma Narrows bridge had famously fallen down in 1940 after going into oscillations in a strong wind; it has become the technical example of destructive resonance in structures. A replacement was built -- I later found out it opened in 1950, having been delayed by the war -- and now a second, wider suspension bridge is being built alongside the earlier one to accommodate more traffic. There was a park down on the western shore where I could take pictures; fortunately I had my old Coolpix, which I can fit with a wide-angle lens, and managed to get some shots of the entire spans. My zoom Coolpix then got me a few nice closeup shots of the construction gear on top of the towers of the new bridge.

Tacoma Narrows bridge

However, due to construction of the new bridge it turned out that I had to go five or ten miles out of my way through Gig Harbor to the west to get back across the old bridge again. Although Seattle-Tacoma traffic is bad, I was able to avoid dangerous blunders this time around, my only real difficulties being caused by the occasional blockages due to accidents -- get traffic of that density, and simple probability makes them relatively common -- and construction work.

The region's traffic problems are not only due to the population density, but also to the fact that the terrain, covered with hills and broken up by bodies of water of various sorts, tends to constrain the road network. There have been initiatives to put in a light rail system, but they've always been shot down -- the region is strong "Not In My Back-Yard" territory.

I remember how, decades ago, Seattle had a system of electric buses, much like ordinary gasoline-powered buses but using a pantograph system to obtain power off of a cluttered grid of overhead lines, with sparking and snapping when a bus bounced on the pavement. Nowdays, they get by with double-length segmented hybrid buses -- interesting machines in themselves, I wish I'd got a good shot of one, but I doubt as effective as a real light rail system with its dedicated rights-of-way. [TO BE CONTINUED]



* INFRASTRUCTURE -- WATERWORKS (3): One of the interesting questions relative to waterworks system is: where did the water we are drinking come from? Possibly the more unsettling way to rephrase that question is: where, exactly, has that water been?

The general rule for municipal water systems is that each person consumes about 570 liters (150 US gallons) of water a day. Obviously nobody can drink that much water, with the water also used to shower, run the washing machine, water the garden, and so on. A typical municipal water system has four primary components:

Cities may also have local subsidiary reservoirs to keep the water flowing in case the main reservoir or its distribution system are shut down for some reason.

* Actually, some lucky cities don't need a reservoir. Philadelphia, for example, gets all its water direct from the Delaware River. Other cities are after all the water they can get. Los Angeles is the best-known case, with its wide-flung water network and long-standing stories of ugly water politics and corruption. Water supply can be a big political issue, the politics becoming nastier as water becomes more scarce: water disputes over the Jordan River have occasionally been conducted with artillery barrages and airstrikes.

A reservoir is nothing more than an artificial lake, if one that has to be as free of various organisms as possible. Algae and other aquatic plants are a particular nuisance, since they give the water a nasty taste. Runoff of fertilizer from lawns and farms tends to encourage their growth. A sack of copper sulphate is sometimes towed around the surface of a reservoir as a herbicide.

Depletion of oxygen is another problem, since it encourages the growth of "anaerobic (non-oxygen-using)" bacteria, which produce a sulfurous taste. The treatment of course is to "aerate" water, traditionally using fountains, but these days the preferred scheme is to use a compressor to drive air through a pipe into a "header" full of small holes, laid on the bottom of the reservoir. A reservoir will have a foaming spot on the surface over the header. Incidentally, the header doesn't aerate the water directly, instead creating a current that "turns the water over", dragging aerated water near the surface back down to the bottom.

* The system for drawing water off the reservoir may be as simple as a pipe, but large water systems may have big, relatively complicated gatehouses to do the job. No matter what the scale, the intake has to be screened to prevent foreign materials from invading the water system. There are several levels screens, the first barrier being a "trash rack", made of iron bars or gratings to stop the big foreign objects. This level is followed by other levels to block leaves, such aquatic plants as survive in a reservoir, and of course fish and other aquatic creatures.

There is always the threat of foreign materials clogging the screens. This problem is usually dealt with by limiting the rate of flow to about 30 centimeters (1 foot) per second or less. This means big intakes and big screens. Ice fouling can be a problem in northern climates; in some parts of the country, intake ports are also threatened by the zebra mussel, an imported mollusc that has become a nuisance that can clog intake ports.

* Some towns may draw part or all of their water supply from wells; homes in rural areas often get their water from wells. The old-fashioned open well is a thing of the past, having been replaced by nothing more nostalgic than a capped pipe sticking up out of the ground. The pump head is at the bottom of the well, which is also screened to prevent the well from pumping up sand and gravel.

In a small well, the pump head is driven by an electric motor, which is also located at the bottom of the well. For larger wells, the pump drive is on the surface, driving the pump head through a long shaft. The larger wells will generally enclose the drive in a shed around the top of the well, with the shed also featuring electrical switchgear -- the pump drive can draw a lot of power -- plus valves, water meters, and taps for checking water quality.

* Whatever the source of the water, it still has to be transported to the municipal system that makes use of it, using aqueducts and pipelines. This is another major component of the water system.

The Romans, skilled engineers that they were, built aqueducts that followed the "hydraulic grade line", which in simpler terms means: "They knew water flowed downhill." It doesn't require much of a slope to keep water flowing, in fact the slope can be so low that it is hard to figure out which direction "downhill" is except by watching which way the water goes. In any case, it took a lot of work by Roman engineers (and their slaves) to make sure that they built an aqueduct that was consistently downhill from source to destination.

Roman aqueduct, Spain

The obvious problem is that things like hills get in the way. The Romans would tunnel through them if they had to. One of the issues with Roman aqueducts was that they were generally open troughs. In modern times, it is possible to use pipes that can use a siphon effect to get over obstacles. The siphon's a simple concept: it is possible to get water to flow up above the level of a source as long as it falls back down to a drain that is lower than the level of the original source -- with the catch that the siphon has to be filled by some effort before the siphoning can begin. In this way, water can get over hills. The same principle can be used in "inverted siphons" to get across valleys.

The rate of water flow in an aqueduct is about as fast a quick jog. The actual amount of water delivered is simply the rate of flow times the cross-section of the aqueduct. Flow through an open trough can be regulated by what is called a "weir", a horizontal gate that can be raised or lowered to adjust water flow. In pipelines, flow is controlled by valves, which are usually installed at the higher points of the pipeline, where the pressure and stress on the valves is the least.

If we turn on a faucet that has a hefty flow rate, we may notice that if we shut it off suddenly, the result is a loud THUMP and the pipes might vibrate a bit. This is called "water hammer" and it's just the momentum of the water flow slamming into the closed valve. For aqueducts with a large water flow, water hammer can generate a lot of force -- and can be destructive. The fix is to put a "surge tank" near the regulator valves to act as a "shock absorber".

Sometimes terrain makes it impossible to set up aqueducts that can rely on hydraulic grade and siphons to deliver the water. The solution is obvious: set up a pumping station at the reservoir or near it. A pumping station looks a little bit like a dam hydropower station, with big pipe systems and a heavy-duty electrical system attached to it, but in a pumping station the pipes will be above reservoir level -- of course, if they were below the hydraulic grade would do the job -- while the opposite is true for a hydropower station.

* Before moving on to the "end use" part of the water system, it's worthwhile to consider the system of reservoirs and aqueducts that supply two great American cities, New York and Los Angeles.

New York relied on wells into the 1840s. They became increasingly inadequate and a series of fires finally forced a search for a better solution. The result was the first Croton Aqueduct, which ran about 64 kilometers (40 miles) to the north along the east bank of the Hudson River. It dumped its water into a reservoir in Central Park -- that reservoir's still there -- which in turned sent water to a distribution reservoir, decorated with Egyptian motifs, at Fifth Avenue and 42 Street, where Bryant Park is now.

By 1885 the city had grown by a factor of four and more water was needed. A bigger dam was built at Croton while a new underground aqueduct was built to carry the water. Even as the new system was being completed, it was still seen as not enough, and so another underground aqueduct system using two tunnels was built, linking to the Catskill Mountains farther to the north than Croton and on the other side of the river. Since the 1970s, work has been proceeding on a third tunnel, 96 kilometers (60 miles) long, to be completed no earlier than 2020. When it's done, the older tunnels will be given some long-overdue maintenance -- no serious work has been done on them since they went into operation.

The Los Angeles water story is interesting in a different way, and features a hero, or villain if you prefer, in the form of William Mulholland. He started out as a ditch tender or "zanjero" and rose to become the master of the Los Angeles Department of Water & Power.

In 1904, Los Angeles had 175,000 citizens, and Mulholland came up with a way to get them water, by running an aqueduct from Owens Valley, 400 kilometers (250 miles) to the north and on the other side of the Sierra Nevada Mountains. The Los Angeles Aqueduct was in operation by 1913. Owens Valley farmers didn't appreciate it and they spent a decade fighting it in court, occasionally resorting to dynamite instead of litigation. They finally had to give it up. Tempers were hot enough over the matter that when the Saint Francis Dam, plugging a local reservoir in the hills north of Los Angeles, gave way out on the night of 12 March 1928, killing at least 400 people, Mulholland suspected sabotage. It appears that it had actually been built on unsound terrain.

By then, the growth of Los Angeles meant much more water was needed, and so a plan was devised to obtain water from the Colorado River, using a dam built on the Arizona state border 385 kilometers (240 miles) away. Arizonans didn't like the idea of Los Angeles taking their water either, and so in 1934 a contingent of Arizona state militia was sent on a borrowed ferryboat to stop construction of Parker Dam. The "Arizona Navy" failed and so did court challenges.

Now the Owens Valley line has been extended farther north to get water from Mono Crater, near the Nevada state border. A second aqueduct was built alongside the lower part of the original aqueduct to handle the increased flow. Los Angeles also obtains water from the canals of the State Water Project from Oroville Dam, north of Sacramento, and Shasta Dam, near the Oregon state border. The network now extends its tentacles over the width and height of the state -- and it's still not enough. [TO BE CONTINUED]



* SKY JAM: In the 1960s, the flamboyant Bill Lear came up with a design for a low-cost mini-jetliner for business executives, with his "LearJet" setting off a revolution in private flying. Such "executive jets" have been rich man's toys, but now new "very light jet (VLJ)" designs are becoming available that substantially lower the barrier to entry. Imaginative business schemes -- such as increasingly popular fractional (shared) ownership, plus lease, rental, and air taxi arrangements -- have been lowering the bar even further.

The problem is, according to an article in BUSINESS WEEK ("Snarl In The Sky" by Christopher Palmeri, 5 June 2006), that private jet traffic is seriously overloading the runways and airways. The number of US companies owning executive aircraft has doubled over the last decade, and the arrival of the VLJs is expected to boost ownership. While private jets often use smaller airports, they still operate in numbers from major airports hubs, and as far as the air traffic control (ATC) system is concerned, tracking an executive jet in flight is just as much work as tracking a jumbo jetliner.

That strains the ATC system. The issue is that private jets pay much smaller fees to support the system than jetliners, despite the fact that the actual cost of dealing with the two is about the same. In 2005, the airlines paid about $9 billion USD into the system, with the private sector paying $600 million USD. The US Federal Aviation Administration (FAA) is now considering changes to the rules. One idea is to eliminate taxes on air fares and fuel in favor of charging user fees based on how far an aircraft flies, regardless of whether it is a private VLJ or a jumbo jetliner.

At McCarran International Airport in Las Vegas, ATC officials are trying to deal with private jets, which provide about a third of the airport's traffic. Private jets and commercial jetliners use different runways, but while they're in the air the machines have to be dealt with more or less equally. Private jet pilots tend to file flight plans just before takeoff, which makes their operations relatively unpredictable and a headache to controllers. Sometimes controllers will call up private jets waiting to take off at other airports and tell them to wait for a bit since McCarran is congested. The FAA has sent letters to private aircraft operators to ask politely that they not use McCarran at peak times, like Sunday morning. Clark County, which owns McCarran, is building up the smaller Henderson Executive Airport to the south and providing subsidies to help encourage private pilots to operate there.

Many private pilots claim they are being cooperative and that the drive to shift more of the funding load to them is unjust: in terms of the total number of passengers carried, they really are small players. However, the US ATC system is now being redesigned, generally around the Global Positioning System (GPS) navigation satellite network, with phase one to be complete in 2010 at a cost of $600 million USD. The FAA is trying to figure out how to get users to bear the cost of the update, which is absolutely essential to keep aircraft flying safely.



* SYSTEM ON PACKAGE: Every technophile is well aware that the density of electronic devices on silicon chips has been doubling at about a rate of once every year and a half for several decades, a phenomenon known as "Moore's Law" after digital systems pioneer Gordon Moore. What's not so well known is that packaging of integrated circuits (ICs) into complete systems hasn't come close to following the same doubling curve. To be sure, there have been improvements, with the old "through-hole" printed circuit boards (PCBs) with their nests of wire-lead components having been generally replaced by surface-mount PCBs with miniaturized resistors, capacitors, and other components soldered onto the board.

Now, according to an article in IEEE SPECTRUM ("Moore's Law Meets Its Match", by Rao R. Tummala, June 2006), researchers are trying to improve electronic system packaging to provide gains in density at a rate comparable to or exceeding Moore's 18-month doubling curve. A group of researchers from the Microsystems Packaging Research Center (MPRC) at the Georgia Institute of Technology in Atlanta, Georgia, is pushing a "system on package (SOP)" scheme that could be used to build full-function personal computers the size of a credit card, or sensor systems that could be swallowed as a pill to monitor body functions, relaying data using wireless communications.

SOP defines what might be called a "super IC", embedding silicon ICs on a multilayer substrate along with micrometer-scale thin-film versions of discrete components, replacing discrete components in traditional small-footprint discrete packages. The footprint shrinks by orders of magnitude. That not only reduces the size of the system, it also increases speed and reduces power consumption by making signal propagation paths shorter.

SOP systems integrate ICs with thin-film antennas, capacitors, inductors, resistors, filters, crystals, and waveguides. Optoelectronic systems can be integrated into the SOP, integrating lasers, diffraction gratings, detectors, and fiber-optic links. For biosensing applications, an SOP can add sensors based on micro-electromechanical systems (MEMS) or new nanotube technology. When other technologies come down the road, they can be added as well.

The fact that SOP combines a wide range of different technologies can be a challenge since different types of devices -- a digital processor and a wireless radio frequency (RF) interface, for example -- may use different supply voltages and may have to be isolated from each other. A wireless interface could potentially jam the processor, for example.

The MPRC was founded in 1993 as the result of a proposal to the US National Science Foundation (NSF). The NSF granted the money and businesses have been involved as well, with the MPRC working with Advanced Micro Devices, Asahi, Ericsson, Ford, Hitachi, IBM, Intel, Matsushita, Motorola, NEC, Nokia, Samsung, Sony, and Texas Instruments. Other organizations around the world are working on similar SOP technologies.

SOP is an emerging technology. Pieces of it are becoming available now, but two things are needed to make it a reality. First, computer-aided design systems must be developed to permit the layout and validation of SOP systems of enormous complexity. Second, new manufacturing processes have to be set up to produce SOP modules on large scale in a cost-effective and reliable way. Although both these requirements require a large amount of effort and capital outlay, they do not represent unconquerable challenges to the electronics industry. The progress of electronic systems over the last forty years has been breathtaking; SOP hints that it's not quite run out of steam.



* JAPAN RECONSIDERS: I tend to track news about Japan, not merely because I like Japanese pop culture, but because there's something fascinating about the mismatched relationship between Japan and the US. Given the cultural differences, it somehow seems surprising that we've only had one war between the two of us -- and from that point of view, even more surprising that the two countries always seem to end up having strong common interests to keep their "odd couple" relationship going.

After the World War II, the American occupation authority imposed a constitution on Japan that, through Article 9, explicitly renounced war except in self-defense. This was not at all unpopular with the Japanese, who felt that the nation's wartime militaristic leadership had led the country to a staggering catastrophe. Ironically, although the Americans had wanted to keep Japan almost completely demilitarized, the Cold War and the Soviet Bear to the northwest meant that Japan was allowed, even encouraged, to build a fairly strong military. However, the Japanese called their military the "Self-Defense Forces (SDF)", and they were dead serious about the label. That suited the Americans fine; the US established a grid of major military installations in Nippon to support "forward-based forces" that could react to military emergencies in the region, giving the US the ability to project power in the region, while the SDF handled the defense of the islands and the seas around them.

According to an article in THE ECONOMIST ("A Giant Stirs, A Region Bridles", 13 May 2006), after the end of the Cold War the military relationship between Japan and the US had to be re-examined. In 1996, US President Bill Clinton and the late Japanese Prime Minister Ryutaro Hashimoto agreed to start the discussions. After ten years, they have been completed. The interesting thing about the new order -- the biggest reorganization of the US military presence in the Pacific since the Vietnam War -- is that, while it readjusts the positioning of American forces to reduce long-standing frictions, it also reaffirms the military relationship between the two countries.

The American military presence is at its densest on the island of Okinawa in the south, and that's where the frictions have been the worst. Every now and then, one of the Marines stationed on the island would assault and sometimes murder one of the local femmes, unsurprisingly leading to ill will. In the new scheme, 8,000 Marines and their families will be relocated to American-controlled Guam by 2014, and the irritating Marine Futenma air base will be closed. That land will be passed back to the Japanese, with a local property boom expected to follow. A new floating heliport will be built off the east coast of the island to support Marine operations.

In addition, some American military air assets now operating from Atsugi air base near Tokyo will be relocated to Iwakuni in the south, near Hiroshima. There will be a wide range of small reshuffles, with units shifted from Japan to Guam or even Hawaii. The Japanese government will foot a good chunk of the bill for the relocations, and will build up the SDF to help fill gaps left by the vacating Americans. On their part, the US military feels the reorganization will actually improve their ability to respond to emergencies in the region.

* The fact that the reorganization will raise the profile of the SDF is one of the key points of the matter. For fifty years, Japan has been pacifistic, but confronted with a belligerent and erratic regime in North Korea, as well as a Chinese military build-up, attitudes toward the previously sacred Article 9 are starting to shift. The Japanese had actually not been too concerned about emerging Chinese power until Beijing encourage public anti-Japanese agitation as a means of boosting the popularity of the autocratic ruling Communist party. In Japan, the ruling Liberal Democratic Party (LDP), now under Prime Minister Junichiro Koizumi, believes in a Japan with a stronger military, the voters clearly rejecting smaller opposition parties with a less assertive line.

No examination of the details suggests that Japan wants to take another stab at military domination of the Far East; none but the most rabidly nationalistic Japanese would even think it desireable. The changes in mindset are modest and gradual, focused on making Japan more assertive in regional affairs. The Americans have been supportive, for example providing technical assistance for the development of a spy satellite system to keep an eye on North Korea. Indeed, some American officials suggest that the pace of change isn't aggressive enough.

Japan's neighbors find any rise in Japan's military profile only too aggressive. Chinese and Koreans have long memories of the brutalities of the Imperial Japanese Army; they would find it easier to forget if the Japanese seemed more willing to repudiate their past misdeeds, but such admissions as have been made have always seemed modest and reluctant. Much worse, Prime Minister Koizumi has repeatedly visited the Yasukuni Shrine in Tokyo to honor Japanese war dead. There's no harm in that as stated, but the Yasukuni Shrine explicitly honors Japanese military leaders who were convicted of war crimes, and loudly states that Japan's war was one of liberation of Asians against Western colonialism -- while many other Asians see it instead as having been an attempt to substitute a Japanese colonialism that was just as harsh or worse in its place.

Given some of the rabid anti-Japanese campaigns in China, it's not too surprising that Japanese citizens are feeling even less inclined to be apologetic. However, the end result has been a set of petty oceanic border squabbles with China and South Korea. There is an increasing mutual perception that all the players need to start acting more like grown-ups and take constructive actions instead of simply bickering. Certainly it does not make sense for Japan to build up a more assertive military and then fail to acquire a diplomatic system working towards the same political goals. Ideas are being floated for joint search-and-rescue missions, as well as new procedures for talking out problems. If nobody has forgotten the last major conflict to engulf the Eastern Pacific, that also means they all can remember what could happen if people stop trying to deal with each other in a peaceful fashion.



* ELECTRIC BUGS: As described in an article in BUSINESS WEEK ("The Tiniest Power Plants" by John Carey, 5 June 2006), the US Naval Research Laboratory (NRL) has been operating a sensor buoy in the Potomac River that is powered by an unusual source of electricity: bacteria living in the river mud below. Ice floes in the river swept off the buoy, but as Leonard M. Tender, the NRL researcher running the demonstration, put it, the buoy would have otherwise run indefinitely.

The scheme was based on a bacterium named Geobacter. It metabolized organic materials that fell to the river bottom, with the bacteria releasing carbon dioxide and producing electrons. A system of electrodes was buried in the mud to draw off the electrons and ship them over a cable to the buoy. The NRL effort was intended to pave the way for scientific and military sensor systems that could obtain power from the lakes and seas where they were planted.

Although the field of bacterial power is in its infancy, some of its advocates are extremely enthusiastic about its potential. Algae are already being used on a trial basis to produce fuels from smokestack emissions, providing both energy and emission control. Microorganisms could be genetically modified to act as little "factories" to produce the desired end product efficiently.

Researchers working on such genetically-engineered micro-organisms see them as commonplace in two decades. Enthusiasts envision wastewater treatment plants or septic tanks that also produce electricity, or even power generation grids lying in the sea bottom mud. The new biotechnology could lead to an economic revolution, allowing poor agricultural countries to become wealthier energy exporters. All that remains to be seen, but the potential remains intriguing.

* ANOTHER MONTH: I ran across an article in SCIENTIFIC AMERICAN on the Sudoku puzzle that's now all the rage -- oddly, it's a late-1970s American invention that caught on in Nippon, crossword puzzles not making a lot of sense in the Japanese language, and was more recently imported back to the USA. It was called "Number Place" originally and the Japanese used that name, the name "Sudoku" being invented for the new American market to give it a Japanese import flavor. Don't ask me what logic this follows -- I just work here.


Whatever you call it, it was intriguing: a 9x9 grid seeded with numbers, with the goal of the game to fill up the grid with the digits 1 through 9, never using the same digit twice in a row or column. Apparently the general concept of a grid with N squares on a side and filled with N symbols which are never repeated in any row or column goes back to the Middle Ages, with the great 18th-century Swiss mathematician Leonard Euler giving such contraptions the name of "Latin squares."

I started to think about it and then realized: NO NO NO NO NO! I don't have time these days to get sucked into something like this.

* I'm overly busy, as I have been all year. Personal business has been keeping me in a bind, but other factors, such as building up the website's photo archive, have also cut into time to get other things done. I'm pushing on getting photos uploaded as fast as I can, since once I get all the archival pictures online I'll only have to add new pictures as I take them. Instead of five uploads a day, it'll be more like five uploads a week.

I think I'm in the "early infatuation" phase of my photographic work, but after taking pictures of obvious things, I'll have mined them out and it will be harder to find interesting things to shoot. Some classes of objects turn out to be more interesting than expected when I shoot them, others less. When everything was in bloom this spring, I took well over a hundred shots of flowers, but as it turns out I find them a dull photographic subject, and I only kept about six. In any case, eventually the growth rate of the photo archive is likely to slow down.

Although I'm having trouble keeping up with some of my monthly work, the blog is going full steam, at least from a production point of view. I've got almost an entire month of articles prewritten. This is not out of any determination to pile up articles, it's just that I've been finding interesting things to write up faster than I can release them. There are worse problems to have, but I'm going to have to figure out how to slow down this merry-go-round since it is eating up a lot of time.

I did manage to complete my five-chapter history of balloons and ballooning. I'd had some small and unsatisfying articles on parts of the subject for some time and had been wanting to build them into something more satisfactory. It turned out to be something of a scavenger hunt to put together, the available information being spotty, and the end result leaves something to be desired -- but still, I haven't found a survey that covers the same range of material. I'll go back and clean it up in six months or a year; sometimes just letting work lie fallow for a while makes it fall into place when I come back to it.