122 
Drought of 1870 and 
experimental wheat-field in January, 1869, when it was supposed 
to be in a state of saturation ; whilst the amount in the subsoil 
of the uncroppcd land Avas not only considerably higher than 
in that of the cropped land, but considerably higher also than in 
that of the saturated wheat soil. We shall recur presently to the 
difference in the percentage of moisture in the soils and subsoils 
of the different fields which have been referred to, but must first 
direct attention to the more special application of the results now 
under consideration. 
The following Table shows the number of tons of water per 
acre retained to the total depth of 51 inches, or 4^ feet, by the 
uncropped and the cropped land, and the difference between 
the two. The upper line gives the amounts calculated according 
to the actual weights of the measured samples of soil (exclusive 
of stones), and the lower line the amounts, assuming that (exclu- 
sive of stones), the dry or barley soil would weigh 18, and the 
Avet, uncropped or fallow soil \Q\ million lbs., to the depth of 54 
inches : — 
Table X. ■ — Tons of Water per Acre to the depth of 54 inches, in Fallow 
Land, and in Land Cropped with Barlej^ 
Samples collected June 27th and 28th, 1870. 
Water pee Aoke. 
Fallow Land. 
Barley Land. 
Difference. 
According to experimentally determined! 
Tone. 
2875 
Tons. 
1951 
Tons. 
924 
According to assumed average weights'! 
2GG8 
1775 
893 
2772 
1863 
909 
On whichever basis the calculation is made, the indication is 
that there were about 900 tons less water per acre in the soil and 
subsoil, to the depth of 4 feet 6 inches, where the barley had 
grown than where the land was fallow. It may be, that part of 
the excess in the uncropped land was due to the shelter from 
surface evaporation since the last preceding heavy rain, by the 
laying of soil upon it for a few days, as above referred to. 
But even supposing a liberal deduction on this account, the 
evidence would still point to the conclusion that there had been 
a higher rate of exhalation by the growing crop than 300 parts 
of water for every 1 part of dry substance fixed ; for it may 
