58 Chronicles of Science. [Jan., 
very properly requires them to keep out of the rivers. It is also 
reported from Lodge Farm that the sewage has been successfully 
and profitably used in the growth of mangold wurzel, cabbages, 
Lucerne, potatoes, and celery ; and that, where applied in dry weather, 
it has largely increased the yield of wheat. In all these cases, how- 
ever, the experiments were on a small scale, and require confirmation. 
The area in grass, on the other hand, is quite enough to enable a 
trustworthy inference to be drawn. 
It is in some degree connected with this subject (for the large 
addition to our supplies of succulent grass which is certain to be 
the first result of sewage utilization, will be somewhat difficult to 
turn to account), that the question of artificial haymaking and 
harvesting has occupied a good deal of attention during the past 
season. Mr. Gibbs, of Gillwell Park, Sewardstone, has patented an 
apparatus by which air heated in a furnace (and the ordinary agri- 
cultural locomotive engine may be used not only for the heat but the 
power required) is driven by a fan through sheaves of corn, which, 
wetted purposely for the experiment, were dried at the rate of 250 an 
hour. And this speed would, no doubt, be much greater if only the 
last portions of natural moisture had to be driven off, which hinder 
the completion of harvest work in a difficult season. Even, how- 
ever, if the reported speed of four sheaves per minute should not be 
exceeded, that would be equal to the clearance of an ordinary crop 
at the rate of four or five acres a day; and this would often be of 
great service to the farmer in a wet harvest. 
As regards the grass and other green crops of the farmer, it is 
an improvement of them, as the food of cattle, to get rid of a large 
proportion of the water which they naturally contain. And this is 
especially the case when they are used as winter food. It is some- 
what interesting, therefore, to find that an attempt to produce a dry, 
or nearly dry cake from pulped, dried, and pressed mangold-wurzel 
roots, has been made, and that it has been found extremely nu- 
tritive in an experiment reported by Mr. Hugh Smith, of Great 
Hadham, Herts. Five sheep put up on May 26, to feed on oilcake 
and pasture, made 262 lbs. of increased live weight during twenty 
weeks, having consumed 72 cwt. of oilcake ; and other five sheep 
fed on similar pasture, along with mangold cake, prepared from 
3 tons 3 cwt. of raw mangold root, made 266 lbs., almost exactly 
the same increase, in the same time. The oilcake cost 4d. 9s., and if 
the 3 tons 3 cwt. of mangold wurzel can be credited with haying 
done as much as that value of oileake did, certainly the roots were 
doubled in efficiency and value to the farmer by being dried. It 
can hardly be contended that this is so; but we may safely gather 
from the experiment that if a certain advantage is obtained im the 
“warm summer months by removing a large proportion of the cold 
water which is given to our fattening stock in mangold wurzel and 
