The Proper Office of Straw on a F<irm. 
163 
novelties. If his estimates differ from those of otlicr recent 
writers, they may perhaj)s be I'ound to square with a soljer 
view of average results, when others are rashly generalizing from 
exceptional cases. 
These pages arc fully as valuable for the suggestions they 
offer as for the conclusions at which they arrive. Our author, 
indeed, gives us full means of estimating the amount of 
manure which may be made under a given course of feeding 
in boxes or in covered yards, in which respect his calcu- 
lations may be of great service in aiding us to arrive at a 
standard for the composition and value of farm-yard manure, — a 
standard with which all other qualities of such manure must 
ultimately be compared and measured. But boxes and covered 
yards are hitherto the exception and not the rule. When, how- 
ever, he comes to the point which most materially affects the 
majority of farmers, how far this problem is modified when the 
cattle are fed in open yards, or even when the litter is thrown 
out from stalls into such yards, our author does not venture to 
clench his statement ; he has, however, at my suggestion, 
appended a note to his original Essay, in which he calculates 
approximately that the rainfall would add 464 tons of water to 
the 525 tons of manure on which it is supposed to fall. 
This estimate is, however, subject to deductions; 1st, for over- 
flow from the yards, and, 2ndly, from the effects of evaporation. 
It must, however, be borne in mind that the assumed dimensions 
of the yards are very small, such as are not often found except in 
connexion with modern buildings, where waste from overflow is 
carefully guarded against. If the buildings were old-fashioned, 
the area of the yards would probably be much larger, and the 
drippings from the roof would add considerably to the direct 
rainfall ; these two sources of an increased supply of water would 
probably compensate for the overflow. Very little is known as 
to the amount of evaporation arising from a bed of straw, the 
top of which is comparatively dry ; but, as the surface exposed 
is but small, and the situation sheltered, the loss of moisture 
from this cause is probably not great, especially during the 
winter months. Taking Mr. Evershed's calculation as it stands, 
without abatement, 200 tons of litter would, in open yards, 
furnish 989, or, in round numbers, 1000 tons of manure. Con- 
sidering, therefore, that he calculates the amount of rainfall for 
yards only of such moderate area as seem best adapted to 
improved modern practice, it may be reckoned that, in the 
larger old-fashioned yards, the weight of manure to be carted is 
doubled by the rainfall.* This conclusion will be confirmed by 
* The result -will be the same if we allow for the employment of a smaller 
number of yards, and, consequently, fewer head of stock kept for a longer period. 
M 2 
