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						501 Portola Road
						Portola Valley, Calif.
						October 6, 1980
Dear Donna:

Here are some preliminary sketches.  The dimensions do not check any too
well, particularly on the side yard but I think I have a viable plan, that
is, if you have enough water presure to throw 25 feet from the Rain Bird
heads.  For safety from freezing, I think that you should build boxes to
enclose the manifolds.  You might ask the plumber to get someone to do
this as he may have had some experience with freezing problems in your
area which I certainly have not had.  A well designed box cover will be
less of an eye sore than the manifolds, in any case.  Do make sure that
there is enough slope to the piping so that it will drain.  By having the
low points near the heads, the drainage is in an area that is being
watered anyway, rather than at the manifold where it probably is not
wanted. I made an exception in some cases for long runs where this would
make the pipe too deep.  Especial care will have to be taken with the
manifold that is at to far side of the yard, since you will not have the
heat from the house to help out.

I have tried to use a minimum amount of pipe, a total of 400 feet for all
that I have shown. I have shown two lines in the same trench for the back
yard, since I doubt if you would have enough pressure if you used one line
for three heads.  This way there may be enough pressure to run several
sets at once but if there is not you can use the different lines one at a
time.  I would also strongly recommend that you use 3/4 inch piping for
all of the longer runs rather than the flexible hose advertized in the
Rain Jet literature. The 3/4 inch heads are much more expensive than the
1/2 inch heads and are hardly necessary so you could use a 3/4 inch to 1/2
inch elbow or coupler to effect the transition.


I also recommend the use of two elbows at each bend from horizontal to
vertical. This allows one to make the vertical pipe exactly vertical, in
spite of the pitch in the underground portion.  It also relieves pressure
on the underground pipe if the vertical pipe is struck by accident.  My
system at Stanford was not fixed this way at first and I was always having
trouble with under-ground breaks until I fixed all of the heads this way.
One does not tighten the joints quite all the way and while there may be a
little leak at some joints, this is better than a big one.  The vertical
lines should be metal as you suggested and they should be tied to redwood
stakes that are driven in as far as can be done easily, I would think
maybe 18 inches in your soil.

The heads should be as high above ground as seems necessary to insure
reasonable coverage without obstruction by nearby plants.  This is
something that will have to be judged on location, and you may also have
to move some of the heads for the same reason.  As to the kind of
sprinkler heads,- there is a bewildering number of different kinds, some
will water a complete circle (you will want one of these) and others do
not have a very good adjustment mechanism but are cheep.  I would
recommend better Rain Bird oscillating 1/2 inch varieties, in spite of the
cost.  By the way, I talked to one man who had used Rain Jet heads and he
is replacing them all with Rain Bird heads because of troubles with thr
Rain Jet heads.

Material requirements
	probably not complete, and you might buy roughly half the amounts listed
	and do only one side at a time.
200 feet of 3/4 inch pipe for the longer runs (comes in 20 foot lengths, I believe)
200 feet of 1/2 inch pipe or underground hose.
9 lengths 1/2 inch pipe each 2 1/2 ft long, threaded at each end
2 tees for 3/4 inch pipe
9 redusing elbows 3/4 inch to 1/2 inch
10 elbows 1/2 inch pipe
7 elbow coupliers between 3/4 inch plastic pipe and 3/4 inch metal pipe
7 3/4 inch nipples (between drain valves and elbows)
9 adapters between plastic pipe and metal fittings
10 coupler to join pipe sections if 20 foot lengths are used
20 coupliers between hose and metal fittings
9 redwood stakes  2''x2''x 3'
3 manifolds complete including pipes to 6 inches underground,
	air relief valves ,shut-of valves etc.
1 full circle head adjustable range Rain Bird prrefered.
8 adjustable angle of sweep and adjustable range heads  Rain Bird prefered

Please pardon the form of this letter but I did not want to take time to
pretty it up.