A very clever hydrogen pump

I’d like to describe a most clever hydrogen pump. I didn’t invent it, but it’s awfully cool. I did try to buy one from “H2 Pump,” a company that is now defunct, and I tried to make one. Perhaps I’ll try again. Here is a diagram.

Electrolytic membrane H2 pump

Electrolytic membrane H2 pump

This pump works as the reverse of of a PEM fuel cell. Hydrogen gas is on both sides of a platinum-coated, proton-conducting membrane — a fuel cell membrane. As in a PEM fuel cell, the platinum splits the hydrogen molecules into H atoms. An electrode removes electrons to form H+ ions on one side of the membrane; the electrons are on the other side of the membrane (the membrane itself is chosen to not conduct electricity). The difference from the fuel cell is that, for the pump you apply a energy (voltage) to drive hydrogen across the membrane, to a higher pressure side; in a fuel cell, the hydrogen goes on its own to form water, and you extract electric energy.

As shown, the design is amazingly simple and efficient. There are no moving parts except for the hydrogen itself. Not only do you pump hydrogen, but you can purify it as well, as most impurities (nitrogen, CO2) will not go through the membrane. Water does permeate the membrane, but for many applications, this isn’t a major impurity. The amount of hydrogen transferred per plate, per Amp-second of current is given by Faraday’s law, an equation that also shows up in my discussion of electrolysis, and of electroplating,

C= zFn.

Here, C is the current in Amp-seconds, z is the number or electrons transferred per molecule, in this case 2, F is Faraday’s constant, 96,800, n is the number of mols transferred.  If only one plate is used, you need 96,800 Amp-seconds per gram of hydrogen, 53.8 Amp hours per mol. Most membranes can operate at well at 1.5 Amp per cm2, suggesting that a 1.1 square-foot membrane (1000 cm2) will move about 1 mol per minute, 22.4 slpm. To reduce the current requirement, though not the membrane area requirement, one typically stacks the membranes. A 100 membrane stack would take 16.1 Amps to pump 22.4 slpm — a very manageable current.

The amount of energy needed per mol is related to the pressure difference via the difference in Gibbs energy, ∆G, at the relevant temperature.

Energy needed per mol is, ideally = ∆G = RT ln Pu/Pd.

where R is the gas constant, 8.34 Joules per mol, T is the absolute temperature, Kelvins (298 for a room temperature process), ln is the natural log, and Pu/Pd is the ratio of the upstream and downstream pressure. We find that, to compress 2 grams of hydrogen (one mol or 22.4 liters) to 100 atm (1500 psi) from 1 atm you need only 11400 Watt seconds of energy (8.34 x 298 x 4.61= 11,400). This is .00317 kW-hrs. This energy costs only 0.03¢ at current electric prices, by far the cheapest power requirement to pump this much hydrogen that I know of. The pump is surprisingly compact and simple, and you get purification of the hydrogen too. What could possibly go wrong? How could the H2 pump company fail?

One thing that I noticed went wrong when I tried building one of these was leakage at the seals. I found it uncommonly hard to make seals that held even 20 psi. I was using 4″ x 4″ membranes so 20 psi was the equivalent of 320 pounds of force. If I were to get 200 psi, there would have been 3200 lbs of force. I could never get the seals to stay put at anything more than 20 psi.

Another problem was the membranes themselves. The membranes I bought were not very strong. I used a wire-mesh backing, and a layer of steel behind that. I figured I could reach maybe 200 psi with this design, but didn’t get there. These low pressures limit the range of pump applications. For many applications,  you’d want 150-200 psi. Still, it’s an awfully cool pump,

Robert E. Buxbaum, February 17, 2017. My company, REB Research, makes hydrogen generators and purifiers. I’ve previously pointed out that hydrogen fuel cell cars have some dramatic advantages over pure battery cars.

Edward Elric’s Flamel

Edward Elric, the main character of a wonderful Japanese manga, Full Metal Alchemist, wears an odd symbol on his bright-red cloak. It’s called a Flamel, a snake on a cross with a crown and wings above. This is the symbol of a famous French author and alchemist of the 1300s, Nicholas Flamel who appears also, tangentially, in Harry Potter for having made a philosopher’s stone. But where does the symbol come from?

Edward Elrich with Flammel on back.

Edward Elric wears a snake-cross, “Flamel” on his back.

s03_ama

Current symbol of the AMA

A first thought of a source is that this is a version of the Asclepius, the symbol of the American Medical Association. Asclepius was an ancient Greek doctor who cured parasitic snakes under the skin by wrapping them around a stick. In mythology, he was chosen to be ship’s doctor on Jason’s voyage, and was so good at curing that Hades told Zeus he revived the dead. Zeus then killed him and set him among the stars as a constellation (the snake-handler, visible in the winter sky between Scorpius and Hercules). Though the story shows some similarities to Full Metal Alchemist, the Asclepius symbol don’t look like Elric’s Flamel. Asclepius had two daughters, Hygeia (hygiene), and Panacea (drugs?); the cup of Hygeia, below, is similar to the Asclepius but not to Ed’s Flamel.

The cup of Hygia, the symbol of pharmacy.

The cup of Hygeia, the symbol of pharmacy.

Staff of Hermes, symbol of the AMA till 2005

Staff of Hermes, symbol of the AMA till 2005

Another somewhat-similar symbol is the Caduceus, symbol of Hermes/ Mercury, left. It was the symbol of the AMA until 2005, and it has wings, but there are two snakes, not one, and no cross or crown. The AMA switched from the Caduceus when they realized that Hermes was not a god of healing, but of merchants, liars, and thieves. Two snakes fighting each other is how the Greeks viewed business. The wings are a symbol of speed. The AMA, it seems, made a Freudian mistake picking this symbol, but it seems unlikely that Flamel made the same mistake.

The true source of the Flamel, I think, is the Bible. In Numbers 21:8-9, the Jews complain about the manna in the desert, and God sends fiery serpents to bite them. Moses prays and is told to put a bronze snake on staff as a cure – look upon it and you are healed. While one might assume the staff was a plain stick like the Asclepius, it might have been a cross. This opinion appears on a German, coin below. The symbol lacks wings and a crown. Still, it’s close to the Flamel. To get the crown and wings, we can turn to the New Testament, John 3:16-17. “Just as Moses lifted up the snake in the wilderness, so the Son of man must be lifted up … “that everyone who believes in Him may have eternal life.” The quote seems to suggest that the snake itself was being lifted up, to holiness perhaps or to Devine service. In either case, this quote would explain the crown and wings as an allusion to Jesus.

German coin, 1500s showing Jesus, a snake and cross on one side. Christ on the other. Suggests two sides of the same.

German “taller” coin, 1500s showing Jesus on the cross on one side, a snake on the cross on the other. Suggests two sides of the same holiness.

I should mention that Flamel’s house is the oldest still standing in Paris, and that it contains a restaurant — one that would be nice to visit. Flamel died in 1418. His tomb has this symbol but was found to be empty. A couple of other odds and ends: the snake on the cross also appears in a horror story, the curse of the white worm, by Bram Stoker. In the story (and movie), it seems there are serpent-worshipers who believe it was the serpent who died for our sins. If you re-read the lines from John, and take the word “Him” to refer to the serpent, you’d get backing for this view. Edward might have adopted this, either as part of his mission, or just for the hell of it. The following exchange might back up Ed’s desire to be controversial.

Roy: I thought you didn’t believe in gods, Full metal.

Edward: I don’t. That’s the thing. I think they can tell, and it pisses them off.

salvation-army

As for the color red, the color may allude to blood and or fire. In this direction, the Salvation Army symbol includes a red “S” on a cross with a crown and the words “Blood and Fire.” In the manga, life-blood and fire appear to be the ingredients for making a philosopher’s stone. Alternately, the red color could relate to a nonvolatile mercury compound, red mercury or mercuric oxide, a compound that can be made by oxidation of volatile mercury. Flamel claimed the symbol related to “fixing the volatile.” Either that’s making oxide of mercury, or putting a stop in death.

Robert E. Buxbaum, February 9, 2017. I’ve also opined on the Holy Grail, and on Jack Kelly of Newsies, and on the humor of The Devine comedy. If you have not read “Full Metal Alchemist,” do.

bicycle helmets kill

There is rarely a silver lining that does not come with a cloud, and often the cloud is bigger than the lining. A fine example is bicycle helmets. They provide such an obvious good that, at first glance, you’d think everyone would wear one, even without a law mandating it. Why would anyone risk their skull in a bicycle accident if injury were prevented by merely wearing a particular hat? Yet half the people ride without, even when there are laws and fines. There are some down-side to helmets, but they are so small that even mentioning them seems small. Helmets are inconvenient, and this causes people to ride a little less, so what?

hospital admissions for bicycle related head injuries, red, left; and bicycle related, non-head injuries, blue, right. Victoria Australia.

Hospital admissions for bicycle-related, head injuries, red, left scale, and bicycle-related, non-head injuries, blue, right scale. The ratio is 1:2 before and after the helmet law suggesting that helmet law did nothing but reduce ridership.

As to turns out, helmets hardly stop accidental injury, yet cause people to ride a lot less, and this lack of exercise causes all sorts of problems — far more than the benefits. In virtually every city where it was studied, bicycle ridership dropped by 30-40% when helmets were required, and as often as not, those who still rode, rode unhelmeted. There was a 30-40% decrease in head-trauma injuries, but it appears that this was just the result of 30-40% less ridership. You’d expect a larger decrease if the helmet helped, as such.

Take the experience of Victoria, Australia; head and non-head bicycle injury data plotted above. Victoria required bicycle helmets in January 1990. Before then, in the peak summer months, hospital records show some 50 bicycle-related head injuries per month, and 100 bicycle-related, non-head injuries — a 1:2 proportion. Later, after the law went into effect, each summer month saw about 35 bicycle-related, head injuries, and 70 bicycle-related, non head injuries. This proportion, 1:2, remained the same suggesting the only effect of the helmet law was to reduce ridership, with no increase in safety. The same 30% decrease was seen by direct count of riders on major streets, though now a greater proportion of those still riding were flaunting the law, and not wearing helmets.

One reason that helmets don’t help much is that the skull is already a very good helmet. As things stand, the main injury in a bicycle flip does not come from your skull cracking, it comes from your brain hitting the inside of your skull, and a second helmet doesn’t help stop that. There’s no increase in safety, and perhaps a decrease as the helmet appears to decrease vision. In a study of bicycle-injury-related highway deaths, Piet de Jong found that countries with the highest helmet use had the highest highway death rates. The country with the highest helmet use (the USA, 38% helmeted) had the highest cyclist death rate, 44 deaths per 1,000,000,000 km. By comparison, the nation with the least helmet use (Holland, 1% helmeted) had among the lowest death rates, only 10.7 deaths per 1,000,000,000 km. There are many explanations for this finding, one sense is that the helmets hurt vision making all types of injury and death more likely.

An hour or three of exercise per week adds years to your life -- especially among the middle aged.

From the national cancer institute. An hour or three of exercise per week adds years to your life — especially among the middle aged. Note these are healthy weight individuals. 

Worse than the effect on visibility, may be the effect on exercise. Exercise is tremendously beneficial, especially for middle-aged people in a sedentary population like the US. The lack of exercise is a lot more deadly, it turns out, than any likelihood of flying over the handlebars. How do I know? From studies like the National Cancer institute, shown at right. To calculate the cost/benefit of a little riding, less say you ride 3 hours per week at 10 mph (slow roll). The chart at right suggests a middle-aged person will add 3.4 years to your life, or about 10% life extension. Now consider the risks. This person will ride 30 miles per week, or 2400 km per year. Over 35 years the chance of death is only 0.36%. In order to get a 10% chance of death, you’d have to ride, over 2.3 million km, or 1000 years. Clearly the life extension benefit far outweighs the risk from fatal accident.

But life extension isn’t the total benefit of exercise. Exercise is shown to improve metal health, reducing depression and ADD in children, and likely in adults. Exercise also helps with weight loss, and that is another big health benefit (the chart above was for healthy body weight riders). So my first suggestion is get rid of bicycle helmet laws. I would not go so far as to ban helmets, but see clear disadvantages to the current laws.

The other suggestion: invent a better helmet. While most helmets are vented, and reasonably cool while you ride. They become uncomfortably hot when you stop. And they look funny in a store or restaurant. You can’t easily take them off, either: Restaurants no longer have hat racks, and stores never had them. What’s needed is a lighter, cooler helmet. Without that, and with helmet laws in place, people in the US tend to drive rather than ride a bicycle — and the lack of exercise is killing them.

Robert Buxbaum, January 19, 2017. One of my favorite writing subjects is the counter-intuitiveness of health science. See, eg. on radiation, or e-cigarettes, or sunshine, or health food. Here is a general overview of how to do science; I picked all the quotes from Sherlock Holmes.

Rethinking fluoride in drinking water

Fluoride is a poison, toxic tor a small child in doses of 500 mg, and toxic to an adult in doses of a few thousand mg. It is a commonly used rat poison that kills by robbing the brain of the ability to absorb oxygen. In the form of hydrofluoric acid, it is responsible for the deaths of more famous chemists than any other single compound: Humphrey Davy died trying to isolate fluorine; Paul Louyet and Jerome Nickles, too. Thomas Knox nearly died, and Henri Moissan’s life was shortened. Louis-Joseph Gay Lussac, George Knox, and Louis- Jacques Thenard suffered burns and similar, George Knox was bedridden for three years. Among the symptoms of fluoride poisoning is severe joint pain and that your brain turns blue.

In low doses, though, fluoride is thought to be safe and beneficial. This is a phenomenon known as hormesis. Many things that are toxic at high doses are beneficial at low. Most drugs fall into this category, and chemotherapy works this way. Diseased cells are usually less-heartythan healthy ones. Fluoride is associated with strong teeth, and few cavities. It is found at ppm levels many well water systems, and has shown no sign of toxicity, either for humans or animals at these ppm levels. Following guidelines set by the AMA, we’ve been putting fluoride in drinking water since the 1960s at concentrations between 0.7 and 1.2 ppm. We have seen no deaths or clear evidence of any injury from this, but there has been controversy. Much of the controversy stems from a Chinese study that links fluoride to diminished brain function, and passivity (Anti-fluoriders falsely attribute this finding to a Harvard researcher, but the Harvard study merely cites the Chinese). The American dental association strongly maintains that worries based on this study are groundless, and that the advantage in lower cavities more than off-sets any other risks. Notwithstanding, I thought I’d take another look. The typical US adult consumes 1-3 mg/day the result of drinking 1-3 liters of fluoridated water (1 ppm = 1 mg/liter). This < 1/1000 the toxic dose,

While there is no evidence that people who drink high-fluoride well water are any less-healthy than those who drink city water, or distilled / filtered water, that does not mean that our city levels are ideal. Two months ago, while running for water commissioner, I was asked about fluoride, and said I would look into it. Things have changed since the 1960s: our nutrition has changed, we have vitamin D milk, and our toothpastes now contain fluoride. My sense is we can reduce the water concentration. One indication that this concentration could be reduced is shown below. Many industrial countries that don’t add fluoride have similar tooth decay rates to the US.

World Health Organization data on tooth decay and fluoridation.

World Health Organization data on tooth decay and fluoridation.

This chart should not be read to suggest that fluoride doesn’t help; all the countries shown use fluoride toothpaste, and some give out fluoride pills, too. And some countries that don’t add fluoride have higher levels of cavities. Norway and Japan, for example, don’t add fluoride and have 50% more cavities than we do. Germany doesn’t add fluoride, and has fewer cavities, but they hand out fluoride pills, To me, the chart suggests that our levels should go down, though not to zero. In 2015, the Department of Health recommend lowering the fluoride level to 0.7 ppm, the lower end of the previous range, but my sense from the experience of Europe is that we should go lower still. If I were to pick, I’d choose 1/2 the original dose: 0.6 to 0.35 ppm. I’d then revisit in another 15 years.

Having picked my target fluoride concentration, I checked to see the levels in use in Oakland county, MI, the county I was running in. I was happy to discover that most of the water the county drinks, that provided by Detroit Water and Sewage, NOCWA and SOCWA already have decreased levels of 0.43-0.55 ppm. These are just in the range I would have picked, Fluoride concentrations are higher in towns that use well water, about  0.65-0.85 ppm. I do not know if this is because the well water comes from the ground with these fluoride concentrations or if the towns add, aiming at the Department of Health target. In either case, I don’t find these levels alarming. If you live none of these town, or outside of Oakland county, check your fluoride levels. If they seem high, write to your water commissioner. You can also try switching from fluoride toothpaste to non-fluoride, or baking soda. In any case, remember to brush. That does make a difference, and it’s completely non-toxic.

Robert Buxbaum, January 9, 2017. I discuss chloride addition a bit in this essay. As a side issue, a main mechanism of sewer pipe decay seems related to tooth decay. That is the roofs of pipe attract acid-producing, cavity causing bacteria that live off of the foul sewer gas. The remedies for pipe erosion include cleaning your pipes regularly, having them checked by a professional once per year, and repairing cavities early. Here too, it seems high fluoride cement resists cavities better.

math jokes and cartoons

uo3wgcxeParallel lines have so much in common.

It’s a shame they never get to meet.

he-who-is-without-mathematics

bad-vector-math-jokemath-for-dummies

sometimes education is the removal of false notions.

sometimes education is the removal of false notions.

pi therapy

pi therapy

Robert E. Buxbaum, January 4, 2017. Aside from the beauty of math itself, I’ve previously noted that, if your child is interested in science, the best route for development is math. I’ve also noted that Einstein did not fail at math, and that calculus is taught wrong, and probably is.

A British tradition of inefficiency and silliness

While many British industries are forward thinking and reasonably efficient, i find Britons take particular pride in traditional craftsmanship. That is, while the Swiss seem to take no particular pride in their coo-coo clocks, the British positively glory in their handmade products: hand-woven, tweed jackets, expensive suits, expensive whiskey, and hand-cut diamonds. To me, an American-trained engineer, “traditional craftsmanship,” of this sort is another way of saying silly and in-efficient. Not having a better explanation, I associate these behaviors with the decline of English power in the 20th century. England went from financial and military preëminence in 1900 to second-tier status a century later. It’s an amazing change that I credit to tradition-bound inefficiency — and socialism.

Queen Elizabeth and Edward VII give the Nazi solute.

Queen Elizabeth and Edward VII give the Nazi solute.

Britain is one of only two major industrial nations to have a monarch and the only one where the monarch is an actual ambassador. The British Monarchy is not all bad, but it’s certainly inefficient. Britain benefits from the major royals, the Queen and crown prince in terms of tourism and good will. In this she’s rather like our Mickey Mouse or Disneyland. The problem for England has to do with the other royals, We don’t spend anything on Mickey’s second cousins or grandchildren. And we don’t elevate Micky’s relatives to military or political prominence. England’s royal leaders gave it horrors like the charge of the light brigade in the Crimean war (and the Crimean war itself), Natzi-ism doing WWII, the Grand Panjandrum in WWII, and the attack on Bunker Hill. There is a silliness to its imperialism via a Busby-hatted military. Britain’s powdered-wigged jurors are equally silly.

Per hour worker productivity in the industrial world.

Per hour worker productivity in the industrial world.

As the chart shows, England has the second lowest per-hour productivity of the industrial world. Japan, the other industrial giant with a monarch, has the lowest. They do far better per worker-year because they work an ungodly number of hours per year. French and German workers produce 20+% more per hour: enough that they can take off a month each year and still do as well. Much of the productivity advantage of France, Germany, and the US derive from manufacturing and management flexibility. US Management does not favor as narrow a gene pool. Our workers are allowed real input into equipment and product decisions, and are given a real chance to move up. The result is new products, efficient manufacture, and less class-struggle.

The upside of British manufacturing tradition is the historical cachet of English products. Americans and Germans have been willing to pay more for the historical patina of British whiskey, suits, and cars. Products benefit from historical connection. British suits remind one of the king, or of James Bond; British cars maintain a certain style, avoiding fads of the era: fins on cars, or cup-holders, and electric accessories. A lack of change produces a lack of flaws too, perhaps the main things keeping Britain from declining faster. A lack of flaws is particularly worthwhile in some industries, like banking and diamonds, products that have provided an increasing share of Britain’s foreign exchange. The down-side is a non-competitive military, a horrible food industry, and an economy that depends, increasingly on oil.

Britain has a low birthrate too, due in part to low social mobility, I suspect. Social mobility looked like it would get worse when Britain joined the European Union. An influx of foreign workers entered taking key jobs including those that with historical cachet. The Brits reacted by voting to leave the EC, a vote that seems to have taken the upper class by surprise, With Brexit, we can hope to see many years more of manufacturing by the traditional and silly.

Robert Buxbaum, December 31, 2016. I’ve also written about art, good and bad, about the US aesthetic of strength, about the French tradition of innovation, And about European vs US education.

A thought on what Cornwallis should have done 240 years ago

Build a wall.

As we’ve seen, Cornwallis’s actual plan January 1777 failed badly. Clearly, it was a bad mistake attacking Washington at Trenton. I’d asked what he should have done, and note that the British high command answer was that Cornwallis should have withdrawn from Trenton and hoped that Washington would have entered and allowed Cornwallis to trap him in the city. I don’t like this solution as it depends on Washington doing something very stupid.

After thinking a bit, I think Cornwallis should have left a detail of British soldiers, perhaps 2000-3000 and should have built a berm wall (an earthen wall) about the town. Cornwallis should have distributed guns to the Tory inhabitants, or encouraged the inhabitants to form a militia. Washington could still have shot in, but with far less precision than before. And he would now find he’s killing Americans. A likely result would have been the Trentonians shooting back at Washington’s men from Trenton’s rooftops. The combination of civil war and weather would have defeated Washington, or at least drawn him off. This is how we dealt with hostile Indians in the 1800s, and I suspect it could have worked here too.

Robert Buxbaum, December 27, 2016. Here, by the way is some odd Christmas music, and two odd Chanukkah songs. The strong defeated by the weak, the many by the few. In those days, at this time of year.

Cornwallis attacks. Washington goes to Princeton.

In the previous post, I asked what you would do as a general (Cornwallis), December 27, 1776. You command 30,000 troops, some 12,000 at Princeton of at total 50,000 against Washington’s 3500. Washington is camped 12 miles to the south just outside of Trenton with a majority of his men scheduled to leave in three days when their enlistments expire.

In fact, what Cornwallis did, is what every commenter recommended. He attacked at Trenton, and lost New Jersey. Cornwallis left 2-3000 troops at Princeton and marched south. Despite fallen trees, swollen rivers, destroyed bridges — all courtesy of Washington’s men –Cornwallis reached Trenton and attacked. By the time he got there, 2000 of Washington’s men had left, partially replaced by untrained militia. After a skirmish, Washington set up 400 militia to keep the fires burning, and without telling them where he was going “Fall back if the British attack”, he took the rest of his forces east, across frozen fields and swampland, then north to Princeton along the Quaker-bridge road. He later said the reason was to avoid looking like a retreat.

He split his forces just outside of Princeton, and a detachment, led by Hugh Mercer and 350  regulars had the first battle as they ran into the 17th and 55th British regiments as they prepared to escort supplies to Trenton. The British commander, Lt.colonel Mawhood, seeing how few men he faced, sent the 55th and most of the supplies back to Princeton, and led his men to shoot at the Americans from behind a fence. Mercer’s men fired back with rifles and cannon, doing little. Then, the trained British did what their training demanded: they rose up and charged the rebels with fixed bayonets. Mercer, having no bayonets, called “Retreat!” before being stabbed repeatedly, see painting. Mawhood’s men seized the cannon, turned it on the fleeing remnants of Mercer’s men.

General Mercer defeated at Princeton, as Washington shows up.

General Mercer defeated at Princeton, as Washington shows up.

It looked like a British victory, but then General Nathaniel Greene (the fighting Quaker) showed up with several hundred Pennsylvania militiamen. The militiamen had never seen battle, and many fled, after shooting into the British lines with rifles and another cannon and grape-shot. At this point it looked like a draw, but then, Washington himself joined the battle with two brigades of regulars: Hitchcock’s 253 New Englanders and Hand’s 200 Pennsylvania riflemen.

Washington managed to rally the fleeing Pennsylvanians; “Parade with us, my brave fellows! There is but a handful of the enemy and we will have them directly!” And Mawhood, now without most of his officers, ordered a last bayonet charge and fled down the Post Road to Trenton. Washington rode after for a bit “It’s a fine fox chase, my boys!”

James Peale, 1783. John Sullivan and his forces at Frog Hollow. Battle of Princeton

James Peale, 1783. John Sullivan and his forces at Frog Hollow. Battle of Princeton

The rest of the British along with Mawhood, met the rest of Washington’s men, lead by John Sullivan, at a place called Frog Hollow, near where Princeton Inn College (Forbes College) now stands. The Americans opened with grape-shot and the British put up little resistance. Those who did not surrender were chased into town, taking refuge in Nassau Hall, the central building of the university. Alexander Hamilton’s men (he’d been rejected by Princeton) took special enjoyment in shooting cannon into the building. A hole remains in the college walls and a cannonball supposedly decapitated a portrait of George II. About then the New Jersey militia broke in a door, and the British surrendered.

Washington had captured, killed, or destroyed most of three English regiments, took a wagon train of supplies, and left going north following a bit of looting. “Loyalists” were relieved of coins, liquor, shoes, blankets. They ate the breakfast prepared for the 40th, and were gone by 11 AM, heading north — to where?. Cornwallis returned before noon “in a most infernal sweat — running, puffing, blowing, and swearing.” His men looted the town again, but now what?

Was Washington headed to New Brunswick where a handful of British soldiers guarded Cornwallis’s supplies and a war chest of £70,000? He didn’t go directly, but perhaps by a circuitous route. Cornwallis went straight to New Brunswick and jealously guarded the place, its money and supplies. Washington meanwhile ran to safety in the Watchung Mountains outside Morristown. Cornwallis’s 17th claimed victory, having defeated a larger group, but Cornwallis gave up Princeton, Trenton, and the lives of the New Jersey loyalists. Rebels flocked to Washington. Loyalists were looted and chased. Hessians were shot in “a sort of continual hunting party.” Philip Freneau expressed the change thus:

When first Britannia sent her hostile crew; To these far shores, to ravage and subdue, 

We thought them gods, and almost seemed to say; No ball could pierce them, and no dagger slay.

Heavens! what a blunder—half our fears were vain; These hostile gods at length have quit the plain.

 

Robert Buxbaum. December 21, 2016. So now that you know what happened, what SHOULD Cornwallis have done? Clearly, it’s possible to do everything right militarily, and still lose. This is an essence of comedy. The British had a similar Pyrrhic victory at Bunker Hill. I suspect Cornwallis should have fortified Trenton with a smaller force; built a stockade wall, and distributed weapons to the loyalists there. That’s a change in British attitude, but it’s this dynamic of trust that works. The British retreat music, “the world turned upside down“, is a Christmas song.

You are Cornwallis, Dec 29, 1776. What should you do?

Here’s a military thought question: what would you do? It is Dec 29, 1776, and you are General Howe and/or Cornwallis. You command 32,000 troops, a big chunk of the largest and finest expeditionary force that England has ever mustered. Washington’s rag-tag army has shrunk from 25,000 at the beginning of the year to 3335 now. They’re arrayed outside of Trenton NJ following their one victory of the year. Their Christmas raid on Trenton killed 100 Hessians and captured 900. In that raid Washington lost only 6 (two to frostbite), but otherwise his year has been nothing but defeats, and you’d like to make sure his string of bad luck continues.

Washington at Trenton with captured regimental flag. December 25, 1776. Peale.

Washington at Trenton with a captured British flag. Dec. 25, 1776. Peale. What should Cornwallis do now?

You’ve retaken the city and have 4000 or so at Trenton and another 10,000 at Princeton, 12 miles to the north. You can march or stay. In favor of staying: the enlistment of 3000 or so of Washington’s army is up Dec. 31, and they’ve not been fed or paid. They will almost certainly quit. You can thus wait and attack Jan. 1, or attack now and give the rabble another reason to quit. Two other options: hole up and let the weather do the job, or bypass Washington, cross the Delaware, and attack Philadelphia, the colonial capital. Philadelphia is completely undefended. What would you do? What should you do? Making the decision somewhat pressing, Washington’s men keep making skirmish raids in and around Trenton. Shooting cannon or rifles in, killing here and there.

Please post your opinion of what Cornwallis should have done, and in a week or so, I’ll post an account of what Cornwallis actually did and how it played out (not well for Cornwallis).

Robert E. Buxbaum, December 8, 2016, roughly 240 years after the events described. I’ve written about other great revolutionary mistakes, and about the battle of Bunker hill.

How do you drain a swamp, literally

The Trump campaign has been claiming it wants to “drain the swamp,” that is to dispossess Washington’s inbred army of academic consultants, lobbyists, and reporter-spin doctors, but the motto got me to think, how would you drain a swamp literally? First some technical definitions. Technically speaking, a swamp is a type of wetland distinct from a marsh in that it has no significant flow. The water just, sort-of sits there. A swamp is also unlike a fen or a bog in that swamp water contains enough oxygen to support life: frogs, mosquitos, alligators,., while a fen or bog does not. Common speech ignores these distinctions, and so will I.report__jaguars_running_back_denard_robi_0_5329357_ver1-0_640_360

If you want to drain a large swamp, such as The Great Dismal Swamp that covered the south-east US, or the smaller, but still large, Hubbard Swamp that covered south-eastern Oakland county, MI, the classic way is to dig a system of open channel ditches that serve as artificial rivers. These ditches are called drains, and I suppose the phrase, “drain the swamp comes” from them. As late as the 1956 drain code, the width of these ditch-drains was specified in units of rods. A rod is 16.5 feet, or 1/4 of a chain, that is 1/4 the length of the 66′ surveyor’s chains used in the 1700’s to 1800’s. Go here for the why these odd engineering units exist and persist. Typically, 1/4 rod wide ditches are still used for roadside drainage, but to drain a swamp, the still-used, 1956 code calls for a minimum of a 1 rod width at the top and a minimum of 1/4 rod, 4 feet, at the bottom. The sides are to slope no more than 1:1. This geometry is needed. experience shows, to slow the flow, avoid soil erosion and help keep the sides from caving in. It is not unusual to add one or more weirs to control and slow the flow. These weirs also help you measure the flow.

The main drain for Royal Oak and Warren townships, about 50 square miles, is the Red Run drain. For its underground length, it is 66 foot wide, a full chain, and 25 feet deep (1.5 rods). When it emerges from under ground at Dequindre rd, it expands to a 2 chain wide, open ditch. The Red Run ditch has no weirs resulting in regular erosion and a regular need for dredging; I suspect the walls are too steep too. Our county needs more and more drainage as more and more housing and asphalt is put in. Asphalt reduces rain absorption and makes for flash floods following any rain of more than 1″. The red run should be improved, and more drains are needed, or Oakland county will become a flood-prone, asphalt swamp.

Classic ditch drain, Bloomfiled MI. Notice the culverts used to convey water from the ditch under the road.

Small ditch drain, Bloomfield, MI. The ditches connect to others and to the rivers via the culvert pipes in the left and center of the picture. A cheap solution to flooding.

Ditch drains are among the cheapest ways to drain a swamp. Standard sizes cost only about $10/lineal foot, but they are pretty ugly in my opinion, they fill up with garbage, and they tend to be unsafe. Jaguars running back Denard Robinson was lucky to have survived running into one in his car (above) earlier this year. Ditches can become mosquito breeding grounds, too and many communities have opted for a more expensive option: buried, concrete or metal culverts. These are safer for the motorist, but reduce ground absorption and flow. In many places, we’ve buried whole rivers. We’ve no obvious swamps but instead we get regular basement and road flooding, as the culverts still have combined storm and sanitary (toilet) sewage, and as more and more storm water is sent through the same old culverts.

Given my choice I would separate the sewers, add weirs to some of our ditch drains, weirs, daylight some of the hidden rivers, and put in French drains and bioswales, where appropriate. These are safer and better looking than ditches but they tend to cost about $100 per lineal foot, about 10x more than ditch drains. This is still 70x cheaper than the $7000/ft, combined sewage tunnel cisterns that our current Oakland water commissioner has been putting in. His tunnel cisterns cost about $13/gallon of water retention, and continue to cause traffic blockage.

Bald cypress swamp

Bald cypress in a bog-swamp with tree knees in foreground.

Another solution is trees, perhaps the cheapest solution to drain a small swamp or retention pond, A full-grown tree will transpire hundreds of gallons per day into the air, and they require no conduit connecting the groundwater to a river. Trees look nice and can complement French drains and bioswales where there is drainage to river. You want a species that is water tolerant, low maintenance, and has exceptional transpiration. Options include the river birch, the red maple, and my favorite, the bald cypress (picture). Bald cypress trees can live over 1000 years and can grow over 150 feet tall — generally straight up. When grown in low-oxygen, bog water, they develop knees — bits of root-wood that extend above the water. These aid oxygen absorption and improve tree-stability. Cypress trees were used extensively to drain the swamps of Israel, and hollowed-out cypress logs were the first pipes used to carry Detroit drinking water. Some of these pipes remain; they are remarkably rot-resistant.

Robert E Buxbaum, December 2, 2016. I ran for water commissioner of Oakland county, MI 2016, and lost. I’m an engineer. While teaching at Michigan State, I got an appreciation for what you could do with trees, grasses, and drains.