616 The Trials of Grist Mills and Disintegrators at Plymouth. 
Type I. Fig. 1. — This illustrates incidentally the character 
of the question which, as already stated, thrust itself upon the 
attention of the Judges at a very early stage of the competition. 
The Hardy Patent Pick Company's machine, although called a 
disintegrator, cannot possibly be differentiated, as to its grinding 
principle, from a mill. Indeed, there is an excellent domestic 
coffee-mill, made by tens of thousands in Philadelphia, and sold all 
over the world, whose grinding surfaces cannot be distinguished 
from those of the " Devil " disintegrator, except in regard of 
size. Further, a certain C. M. Savoye, of Middlesex, patented 
a flour mill in 1832, which he thus describes: "The grindiug 
surfaces in this mill consist of two concentric rings, having on 
their contiguous surfaces a series of teeth, cut in such a manner 
us to pi*esent cutting edges whether moved to the right or to 
the left. In the upper part" (or inner circumference of the 
grinding rings) " they project a quarter of an inch and diminish 
outward to a plain or even smooth surface, so as gradually to 
reduce the grain to fine flour." If, then, Nicholson's bone-mill 
be not truly a disintegrator, it is evident that the Hardy Pick 
Company's " Devil " is, equallv with it, a mill. 
Type II. Fig. 2.— The "Collision" mills of Messrs. Harri- 
son Carter, and Hall, Robinson & Co., may be regarded as 
physical analogues of that spiritual "kicking against the 
pricks " condemned by the apostle as a waste of energy. 
Originating one knows not where, the idea of grinding by 
percussion has evidently taken some hold upon public credit. 
It consists in violently throwing, by means of rapidly revolving 
" beaters," the materials to be pulverised against the inner 
periphery of a cylinder, which, consisting of steel grids, permits 
such fragments as are struck off at each blow to pass through 
the interstices of the grids, while the body from which they are 
Struck is still further beaten against the bars of its cage. 
Ti/pe III. Fig. 3. — Toothed roller crushing, as already in- 
dicated, is one of the oldest of all methods of milling, and needs 
no description. 
Type IV. Fig. 4. — An exactly similar arrangement to that 
of Coward's is described and figured in Knight's Mechanical 
Dictionary ; balls being used instead of edge runners for 
grinding, while the ground material is carried away by means 
of a fan blast, exactly as in Coward's machine. 
The trials of disintegrators took place on June 20, under 
similar conditions to those which characterised the mill trials, 
no change in the general arrangements being made, save that 
the dynamometer was furnished with stronger springs for the 
purpose of registering a higher horse-power. Preliminary essays, 
