i6 
Colorado Experiment Station. 
water direct, on the other beam, each quarter pound being i%. 
These calculations were checked at three intervals against samples 
of earth taken from the tanks with a butter trier and tested for 
water by drying in a soil oven. 
The soil temperatures used were 50°, 65°, 80°, and 95°. 
The potatoes planted in earth at 95°, in many cases started to 
sprout but all were killed before coming to the surface, so that 
only three cabinets were operated to maturity. 
The quantities of moisture used were: 10% for the long 
row at the left in each cabinet through the entire experiment; 20% 
Figure 9.—Plants grown for the whole period respectively at 80 degrees 
soil temperature (bottom row) and at 65 degrees soil temperature (top row) 
five days after the right hand plants had been changed from a soil moisture 
content of 20% to one of 40%, the next plants from 20% to 30%, the left-hand 
plants remaining at 10% and 20% as from the first. Fiisarl'Kvi content neg¬ 
ative or positive according to the sign.s on th?> tanks. 
