114 
Drought of I'SlO'and 
36 inches ; and allowing one-eighth more for the? wet soil, we 
have 13,500,000 lbs. per acre for its weight to the depth of 
36 inches. Adopting these figures, and the average percentage 
of moisture in the soil of each plot, we have the following 
amounts of water per acre on the respective plots in the two 
conditions : — 
Table VI. 
July, 1868. 
Dry. 
January, 1869. 
Saturated. 
Difference. 
Tons of Water, per Acre, to a depth of 36 inches. 
Plot 2. — With Farmyard Manure . . 
Plot 8a. — With Miner^ Manure and] Am-l 
666 
591 
694 
1396 
1610 
1549 
730 
1019 
855 
Tons of Water, j^r Acre, over (or under) Plot 3. 
Plot 2. — With Farmyard Manure 
Plot 8«. — With Mineral Manure and Am-1 
-75 
28 
214 
153 
289 
125 
Thus we have on the unmanured plot 730, on the dunged 
plot 1019, and on the artificially manured plot 855 tons, more 
water per acre, to the depth of 36 inclies, when the soils were 
saturated than when in the dry condition. As already said, the 
soils would not retain such an amount of moisture at the time of 
the commencement of active vegetation. But, by way of illus- 
tration, it may be stated that if they retained even two-thirds 
of the indicated difference prior to the commencement of the 
drought, and the commencement of active growth in 1868, the 
amount would be considerably more than would be required by 
the unmanured crop, and would supply a large proportion of that 
required by the manured crops, on the supposition that about 
300 parts of water would be exhaled by the plants for 1 part 
of dry substance fixed by them. The soil-resources of moisture 
available to the growing crop would, however, doubtless extend 
beyond the depth to which the examinations refer. Then, again, 
the amount of rain which actually fell during the period of 
active growth, though comparatively small, would, nevertheless, 
be not immaterial considered in relation to the balance of the 
requirements of the crops. 
A very remarkable point connected with these results is, how- 
ever, the difference in the amount of water retained per acre to a 
given depth by the soils of the different plots when saturated. 
