IRRIGATION AND METEOROLOGY. 
'crest of tlie weir was of iron, filed true, and to a knife edge. In 
computing tlie discharge, the following formula was used: 
Q=3,33 1 h 3-2. 
Q=Discharge in cubic feet per second. 
E=Length on weir—17 inches, 
H=Deptli on weir in feet. 
It is believed that the volume used is greater than that em¬ 
ployed in ordinary irrigation, the watering of such small areas in¬ 
evitably entailing considerable waste. 
The soil of the college garden is a o.tifT clay, which has been 
loosened up somewhat by manures; it still, however, absorbs 
moisture very slowly. Nearly the whole of the garden has con¬ 
siderable slope, and in irrigating in furrows, from one-third to one- 
half of the water runs to waste. This fact should be kept in 
mind in considering tne volume required in its irrigation. The 
area of the plat is 2.1 acres; of this, .45 acre is experimental 
grasses and small fruits, the remainder being vegetables. 
The water used on the garden was measured through a box in¬ 
vented by A. D. Foote, C. E., of Boise City, Idaho, the form of 
which is shown in the accompaning illustration, with the difference 
that the water passed out without pressure, the opening acting as 
a notch of adjustible width, the depth to remain constant. The 
depth of water passing through the box for April and May was 
fixed at six inches; after that at live inches. The form of the 
box is such that the regulation of the depth is very nearly 
automatic. 
It was found that when the notch was more than two inches 
wide, the water in the lateral leading from it offered an obstruct¬ 
ion to its free discharge. When the notch was six inches wide, the 
water in the lateral was about one inch above the bottom of the 
notch. A theoretical computation of the discharges under these 
conditions was not considered reliable, and a series of tests were 
made to determine this. The limits of this bulletin will not per¬ 
mit of a description of these test3, from which the following table 
of discharges was constructed : 
