246 The Tlvolufio7i of Agricultural Implemeiits. 
Should roller milling succeed, as will probably be the case, 
in altogether displacing stones, the importance of such a revo- 
lution may be best measured by the fact that 1 25,000 horse-power 
and 18,000 pairs of stones are still employed in grinding flour 
in the British Islands. 
Cattle Food Pregyaring Machines. — It was rare, at the begin- 
ning of this century, to see either a corn-kibbler, a chaff-cutter, 
or a root-cutter, at work upon any farm, while the oilcake 
breaker and the gorse mill were not as yet known. But, since 
the dependence of English agriculture upon live stock has been 
more and more fully demonstrated, cattle-food preparing 
machines have become the largest class of implements at all 
agricultural shows, and the prosperity of the fanner may indeed 
be estimated by the use he makes of them. 
Farm Corn Mills. — Grinding for the purpose of cattle and 
pig feeding has assumed considerable importance since corn 
has become cheap, and the farmer has always on hand a con- 
siderable stock of tail-corn, which, in days antecedent to the 
finishing threshing-machine, found its way to market in the 
Avheat sacks. 
]\Iill stones and roller mills are ill-suited for gristing, which 
is now generally accomplished by means of metal mills. 
Metal Discs were first used by Napoleon on the march to 
Moscow for the purpose of supplying his troops with meal. 
The “ French Military Mill,” as it was called, consisted of a pair 
of cast-iron discs about 1 2 inches in diameter, vertically aiTanged, 
and turned by hand. 
Conoidal Metal Discs were invented by David Selden, of 
Liverpool, in 1831. 
Grooved Roller and Breast. — In 1833, a certain Thomas Don, 
of Westminster, patented a vertical millstone which bore peri- 
pherally against the segmental curve of a second stone of 
rather larger radius than the runner; but Don was himself 
anticipated by Charles Williams, of Southwark, who, in 1810, 
made a metal mill consisting of a grooved roller working 
against a breast formed of a number of knives, screwed together 
so as to form the same curve as the roller, the knives being re- 
movable for the purpose of sharpening. The roller in Williams’s 
machine was kept up to the breast by weighted levers, which, 
while furnishing pressure enough for the purpose of grinding, 
allowed the breast to give way, exactly as in modern practice, 
on the passage through the mill of hard foreign substances. 
Conical Roller and Breast, giving endwise delivery of Meal . — 
Amory Felton, an American, seems to have been the first in- 
ventor, in 1855, of the horizontal conical roller and breast, which. 
