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[Bill Jones <billj AT harborside.com>]

Lee's Easter trip was a big success.  The Indian soup of Peruvian 
tuberous nasturtium (mashua) that we created was truly remarkable.  
Mashua has an incredible yield and never fails or gets eaten by voles, 
but in raw form they have a hideous taste that combines the flavors of 
horseradish and almond extract.  When cooked they're somewhat better, 
since the horseradish taste goes away, but they're still quite almondy.  
Even then they're unrewarding to eat plain, and Peruvians don't have 
many choices for seasoning them beyond traditional Spanish ingredients 
and the native herb _huacatay_ (Tagetes minuta, the nematocidal 
marigold, which we're growing this year, although it sure looks like 
Texas tarragon to me).  Taking the idea from Spanish almond soup with 
onion and cumin, we used the toasted North Indian "five seeds" (mustard, 
cumin, nigella, fennel, and fenugreek) in a soup that featured fresh 
turmeric root along with onions, garlic, and ginger.  It was finished 
with Vietnamese coriander leaf (like cilantro), garam masala (coriander 
and cumin with a dash of pumpkin pie spices), lemon, and pepper.  It was 
the first thing I ever found to be truly wonderful that was made from 
mashua as the main ingredient.

I had hoped that the spirit of Earth Day would bless me with creative 
insights during this last week of April, and now that the May Eve is 
upon us, it has.  I think I've finally threaded the needle, using tiny 
power for water pumping.  The heart of the system will be the buoyancy 
engine that we built last spring.  Several low-pressure air sources can 
be combined to run it.  I think that I can combine homemade power 
sources with the same facility that one can with electricity.  The only 
other reason for preferring compressed air over direct linkage is that a 
situation may require that the well be far from the power source.  The 
power output is lower than with electricity, but the cost is also many 
orders of magnitude lower, so I can easily imagine approaching the 
$1/watt barrier for mechanical application of wind, hydro, and solar power.

It's important to realize that these tiny devices provide power for 
water pumping at a low rate, and that water must be stored for later 
use; the idea is not to pay more for "high power" when you only need a 
certain amount of energy, which can be obtained slowly over long 
periods.  If you calculate just how much mechanical power is required to 
raise 1000 gallons of water per day, by a device that runs continuously, 
it comes out to less than 10 watts!  The only reasons I'm feeding 1000 
watts to my existing impeller pump are 1) it's utterly the wrong pump 
for the job, wasting 90% or more of the energy fed to it on a long lift, 
and 2) so that it can be off most of the time, expending energy in 
short, powerful bursts.  Oh, and 3) everyone else has one.

I'd like to test some simple air pumps that just consist of an outer PVC 
cylinder filled with water, capped off at the bottom, and an inner pipe 
that pumps air through an aquarium check valve when you push the inner 
pipe down into the outer one.  They just have to be tall enough to 
provide the system minimum pressure, which is just determined by how 
deep the buoyancy engine's air injector is positioned.  These are even 
tiny and cheap enough to harness the small wattage generated by swaying 
tree branches.

The solar component is basically a solar-powered still that continuously 
boils and recondenses expensive fluorocarbon propellant, but it's much 
more useful if the pressurized propellant vapor just compresses air 
through a membrane before it recondenses.  It was a little ridiculous to 
imagine running a buoyancy engine on hot propellant directly, since the 
water would have to be heated, and even then the mechanical up-and-down 
motion that results, like an AC power supply, cannot be combined easily 
with other asynchronous processes, as compressed air can (actually it's 
worse than AC, because the latter is easily transformed and rectified, 
and then you can combine two power sources).

Would it be ironic if I told you that I came up with all this because 
I'm not terribly mechanically inclined?  I like the fact that it's all 
schoolgirl safe, bonehead simple, and cereal-box cheap.  Nothing will 
ever fly apart and hit me in the face.  Sparks will never fly everywhere 
and ignite my clothes.  The propellant will never explode the boiler 
because it never needs to reach 3 psi nor more than 130 F., just to run 
a buoyancy engine.  The largest force involved is less than a person weighs.

I would at least like to modify our old 4-cylinder to make it into a 
compressor.  It's desirable to use as high a gear as possible, so that 
it turns fast and produces the largest possible volume of air, since it 
naturally produces a high pressure, which is difficult to combine with 
lower pressure air sources.  I'm thinking of driving it with a regular 
rotary windmill.  Our most useful winds for water pumping always come 
from the north, so it would be feasible to have a rotor that always 
faces north, which would allow a simple belt drive connection between 
the compressor and the rotor.

I looked at the drop in elevation from the creek by the road to a 
convenient location at the center of the upper area, and decided that 
there's promise that a hydraulic ram would work.  I found one on-line 
for only $150, one that would all alone provide all our water needs for 
free, IF the available flow doesn't go below 2 gallons per minute.  It's 
a splendid plan.  The water would be siphoned over to a holding tub, 
which needs to be several inches deep to feed water into the downhill 
run to the hydraulic ram at a high enough rate.  Water runs downhill out 
a drain in the bottom of the holding tub, through a pipe that runs 
straight downhill over 100' to the hydraulic ram.  From there 3/4 of it 
spews out rhythmically, to be siphoned over to peach trees, and 1/4 of 
it is pumped back up to a storage tank.  If the water runs short, then 
we could (at some greater expense) run a water pipe all the way to a 
distant, more reliable, water source, where the landscape is even more 
perfect for a hydraulic ram.

We finally have the ultimate simple method of pumping water from a deep 
well.  Years ago we bought an "emergency well hand pump" that just 
consists of a long tube with a check valve to keep water from flowing 
backward out the bottom.  You're supposed to thread it down a guide tube 
and accelerate it vigorously downward.  I wondered whether it would be 
possible to automate this process.  Just the other day we tested a 
simple catapult system with a lever and a driver weight.  There's a 
hinge at one end of a stick, and the other end thrusts one end of the 
(long) tube down a guide tube.  The driver weight is heavier than the 
water-filled tube, and falls downward on its own schedule, so that means 
that the lighter "load" weight (the tube) accelerates faster than it 
would just from falling.  Water is pushed against the top of the tube 
when the tube accelerates faster than 1 g.  The cool thing is, you can 
prove that there's a maximum amount of acceleration that can be achieved 
from a given driver weight, and it's very easy to find a formula for the 
ideal lever ratio that goes with it.  It's not hard to see why.  If the 
driver weight is too close to the load, then its own inertia dominates, 
and the whole can barely fall faster than 1 g.  If the driver weight is 
too close to the fulcrum, then the driver weight doesn't exert enough 
force on the load to drive it.  Anyway, the ideal lever ratio is just 
given by 2r, where r is the acceleration ratio.  So to provide 2 g's of 
acceleration with the least possible weight requires a lever ratio of 
4.  The necessary driver:load weight ratio is given by 4r(r - 1), which 
equals 8 when r = 2.  Knowing those formulas replaces hours of trial and 
error!  From what I saw in the experiment, it's definitely worth going 
on to test the entire length of tubing on the actual well, since all we 
have to do is place a 2 x 4 on a temporary fulcrum outside the well 
house.  I was also able to show that the absolute maximum height that 
the water can be pushed upward after leaving the accelerating tube is 
just the "extra" acceleration r - 1 times the height of the (long) 
accelerating tube.  We only need to get the water up at most 10' to the 
top of a storage tank, which is only 10% of the well depth, so that 
suggests that much less than 2 g's is required.  It's important to 
realize that this device will never deliver more in one 6' stroke than 
the volume contained in a 6' length of the tube, so more acceleration 
beyond that minimally required is wasted.   The details of how to 
automate the process of picking up the weighted lever and letting it 
drop again aren't difficult either.  It just needs a harpsichord 
mechanism, a hinged "plucker" that pushes against the lever when it's 
pulled upward, because it hits a stop, but hinges when it travels the 
other direction, so that the end slides past the harpsichord string, 
silencing it (or in our case, it will slip past a small cam mounted on 
the side of the catapult lever, to reset for another cycle).  I suppose 
I'd rather have a straightforward hand-operated cylinder-type well pump 
for the buoyancy engine to drive, but the lowest price I could find was 
$140.  So it's a bit much to spend for now, just be able to experiment 
with a buoyancy engine and some compressed air sources.  Besides, I can 
calculate the efficiency of the pump very precisely, so I'll know 
roughly how it will behave when a regular cylinder pump is used, and I 
can still test all the other system components and figure out what the 
output would be with a better pump.  It only has to produce about 2/3 
cup of water per stroke every 5 seconds, or only half that much twice as 
often, to provide us with 1000 gallons a day.

Much later... The garden is all planted, and cold rainy weather 
returned.  It rained over an inch, and now we're working on the last 
tenth of our 70th inch since October 1.  Can you believe the maca 
seedlings are dying from lack of light?  The cucumbers and squash 
haven't sprouted, but the beans did.  I've never seen such great peas, 
though.  My tomato and pepper plants have been under a plastic cover, 
but they were nearing the roof and that's just blight city waiting to 
happen, so yesterday I put on the taller PVC house.  Overall I'm 
thrilled to be rescued from the month-long spring drought, since during 
the heat wave grass flowers shot up faster than my half-dozen sheep 
could eat them.  I'm pretty impressed to see how well the land can keep 
sheep, since all they get is a little flake of alfalfa every evening.  
This year I'll be keeping at least two until late in fall, since new 
Himalayan berry briars are coming up where it was mowed last year, and 
they're ruthless at removing them.  I'm glad that help is on the way, 
since I feel that I've been so good at juggling everything so far, and 
in fact everything is perhaps more perfect here than ever before, some 
little thing's got to go wrong!  I'm especially nervous because twice 
now a lamb has shown up on the neighbor's side of the fence, and I can't 
find the hole.  Now there's a way to lose money fast!  At least with two 
people you have a better chance of herding them back in.

I've decided to make some mash for animals from cheap food sources.  I 
have several bags of old potatoes and yacon tubers from last year, and 
stinging nettle is abundant.  First I'll boil down the roots, then I'll 
just keep adding one batch of nettle after another, mashing well.  
Finally I'll add some ground up dried peas and maybe some corn meal, and 
some salt.  This should be firm enough to cast into sticks and dry in 
the greenhouse, just until it's hard enough to push through hardware 
cloth (like Spatzel) for further drying.

I'd like to wish a happy high school Graduation Day to my niece Lacey.  
Actually she graduated yesterday, but I was unable to make the 1000-mile 
trip.

And happy Memorial Day weekend to everyone.

Bill