52 
BULLETIN 906, TJ. S. DEPARTMENT OE AGEICULTUEE. 
change in design, This valve is provided with a lift gate in the 
bottom so that some of the water can flow to the lower hydrants with- 
out having to be forced through each valve. A much smaller pipe 
could be used for the main distributing hydrant if the spillway pipe 
was set through the lower side of the hydrant, and set on an angle to 
the underground pipe. Smaller spillways could also be -used if this 
plan was followed, without danger from entrapped air. 
Where sandy soil is to be irrigated, and furrows run on a gradual 
grade it is often best to do away with the ordinary stand that ex- 
tends above the ground. An orchard valve or alfalfa valve can be 
cemented to the riser, having the riser 
cut off 4 inches to 6 inches below the 
ground surface. If the valve is set in- 
side the first tree and in every tree row 
it will be no obstruction to cultivation. 
Where sandy soil is encountered it is 
often impracticable to attempt to run 
a number of furrows between the rows 
on account of the rapid percolation of 
water into the subsoil. It is a common 
sight to see sandy ground watered by 
using the ordinary hydrant fitted with 
4 to 6 outlet gates, and either allowing 
all the gates to spill in one main furrow 
or letting the water run over the top of 
the stand. Where flooding or basin ir- 
rigation is practiced there is no need of 
a number of small outlet valves set in 
one hydrant. 
Where flooding is resorted to for al- 
falfa or orchards having very flat grades 
and sandy soil, risers are set at con- 
venient intervals that are capped with 
a special lid. This cap can be removed 
and a portable hood or hydrant attached 
to it (fig. 36). There are a number 
of different types on the market. The best portable hydrant can be 
fastened to the riser before the cap on the riser is removed or 
loosened. Portable pipe made from light-weight galvanized iron can 
also be easily attached to these portable hoods. This arrangement is 
often used where alfalfa is irrigated, but may be used to advantage in 
orchards where soil or grades will not permit of furrows. 
Where steel pipe is used for distributing water, the outlet valves 
are usually the common hydrants or faucets used in domestic water 
Fig. 36. — Distributing hydrant for 
large irrigation heads, such as 
are used in irrigating alfalfa. 
