Relation of Nonava liable Water to Hygroscopic Coefficient 21 
barley plants described by the writer and their presentation of 
the means advocated by him for the estimation of available mois- 
ture in soils are inaccurate, as is shown elsewhere in this publica- 
tion. 1 
GENERAL DESCRIPTION OF THE EXPERIMENTS. 
The experiments were carried out in a greenhouse using water- 
tight galvanized iron cylinders. Except in the case of those with 
desert legumes the cylinders were 6 feet long and 6 inches in 
diameter, containing known amounts of soil and of water. In 
these, seeds were planted and the plants allowed to grow, without 
further addition of water, until they died. On the death of all the 
plants in a cylinder it was opened and the moisture content de- 
termined in 3-inch sections. The distribution of roots in the sub- 
soil was carefully observed and in the later experiments these 
were removed, photographed and weighed. 
SOILS USED. 
Some of the soils used were from the semiarid western por- 
tion of Nebraska, some from the humid eastern portion, and the 
others from the intervening portion of the transition region. The 
physical character of the soils used is shown by their hygroscopic 
coefficients given in Table 1. 
PLANTS GROWN. 
Red Fife wheat was grown in the experiments of all four 
years, milo and Mexican beans in the last two, and Kubanka 
wheat, corn and some perennial desert legumes each in only one 
year. The last mentioned were Prosopis velutina. Acacia Greggi 
and Acacia constricta. 
GREENHOUSE USED. 
The only greenhouse available for the experiments was an 
old. poorly ventilated one. The ventilators in this were im- 
mediately above the only portion of it in which the cylinders 
could be placed. As any rain falling on the cylinders would have 
seriously interfered with the experiments, the ventilators were 
kept closed during threatening as well as during rainy weather. 
A steam-main, which led to another building, and in which the 
steam was kept at high pressure day and night until warm 
weather set in, increased the difficulty of keeping down the maxi- 
mum temperature. The use of whitewash on the glass panes of 
the greenhouse had to be abandoned, as the wheat plants would be 
footnote 2, p. 116. 
