Shoshone journal. [volume] (Shoshone, Idaho) 1884-1931, 1898-02-11
YindmIII SCIENCE.

time yielding $4,000 foot pounds. All
windmills are given by the manufact-
urer certain horse power equivalent,
this capacity being predicted upon what
the windmill is capable of doing in a
wind of twenty miles per hour, and
which is, by the way good stiff blow,
and by far a stronger wind than gener-
ally prevails. A more conservative aver
age upon which to base your calcula-
lions for general purposes, is not TO ex-
coed an average Of more than fifteen
miles per hour. 1t is here proper to
saw that a windmill of any diameter has
greater or less power as the square of
the velocity of the wind in miles per
hour, and therefore mill which would
develop three horse power in fifteen
miles per hour would have but one and
one-third horse power capacity when
the wind was blowing at the rate OF ten
miles per hour. The square or 10 is
225, the square of 10 is 100. A mill OF
any diameter will handle a greater or
less quantity of water as the yertlcle
height of discharge in feet is decreased
or is increased; for instance, mill that
will raise 100 gallons of water per min
ute fifty feet vertically, will lift zOO
gallons per minute twenty-five feet YER
tically, or the same mill will lift fifty
gallons per minute 100 feet vertically.
A cubic foot of water weighs approx
mately sixty-two and one-haf pounds
and contains approximately seven ana
one-haf gallons, a gallon OF wafer
weighing about eight and one-thlro
pounds. It will be of great personal
assistance if you will remember that
the pumping of water is simple me-
chaLical problem, and acquire the |
hab.t of reducing the quantity OF water
to be handled to so many foot pounds.
If you will do so it will save you from
serious disappointment. Perpetual mo-
ton has not yet been discovered. he
member above all things one pound OF
any substance, no matter what SUI
stance. lifted one foot vertically in one
minutes time, or equivalent, requires
a mechanical force of one foot plus
the friction which is due to the means
EMPLOYED. You can lift yourself over
the fence by your boot tops just as
easily as you can get away from THIS
fixed law. A great deal is said to-day
ability to eliminate friction, and that
by this means, or that means they can
discharge a given number or gallons ol
water per minute 4 given numDer OF
feet vertically witt. less power that can
he done nv any orner means OF exactly
fine same principle in every detail. 1t
ought not to take any person long to
make I'D his or ker mind than the per
son making any such statements de-
liberately deceives himself to say the
least. Along this same line OF thought
it is proper to state that exaggerated
ideas prevail to what can be accom- {
plished by the wind for various power
purposes. The pressure of the atmos- {
phere at the sea level is but 14.7 /
pounds per square inch. When the q
wind is blowing at a velocity of twenty
miles per hour, such a wind exerts f
pressure of but two pounds per square 2
foot of surface exposed. Therefore the S
power of a windmill is necessarily lin i
tied by the velocity of the wind and for T
this reason windmills can be used for n
water for irrigation or other b
demanding large volumes of
water to but limited extent, and in all Y
instances where windmills are utilized +,
for this purpose they can be success r,
fully used only in connection with res :,
srvoirs of ample capacities.
An acre of ground contains 6,272,6 $40 y
square inches. If one acre of ground
De covered with water one inch deep, y
We would have a quantity of water al
'qualing PISS gallons or what is u
ermed one acre inch. If the quantity II
# water on the one acre be increased ID
o thirteen inches, we would have what
5 called one acre foot, or 1850 cubic m
eet or 325.S51 gallons of water. 1t is al
onceded that in the semi-arid belt one
cot of water per acre is necessary TO eA
insure the growing, and it seems to be III
established that this quantity of water
Till be demanded principally in two Of
lonths Of the season. To irrigate ten to
cres of land requires, therefore, a to- tn
II of 3,25S.510 gallons of water, and if w
II is applied in the two months. 1t re- go
uires an average of 1925, $50 gallons br
er month. Assuming that windmill by
i'll work to its full capacity, ten hours 10y
er day, thirty days per month, we be-
ould then need for the ten acres of ha
round an average Of 5,431 gallons per br,
our or 81 gallons per minute, or ITO tn.
lllons per minute per acre. Assum 'b
e that this quantity of water must str
} lifted vertical distance OF ten feet. mo
would then require a mechanical wa
rec of 81 (the number of gallons) wa