610 The Trials of Grist Mills and Disintegrators at Plymouth. 
its operation. The mill is supported by a substantial iron 
frame, and occupies a floor-space of 3 feet 9 inches x 3 feet 
6 inches, while the hopper is not too high for the easy discharge 
of grain. The weight of the machine is under 6 cwt., and its 
price, 13?., very moderate. 
Upon going to work, on June 23, the Corbett mill disposed 
rapidly of its 2 cwt. of assorted corn, producing good samples of 
meal designed for feeding purposes, working very steadily and 
noiselessly, requiring little attention, and at once creating that 
" favourable impression " which, subject to confirmation by 
"weighing and measuring," suggests a prize-taker very early in 
a run. The records of the time occupied and power absorbed 
by this, as well as the other mills, will be found collected in 
Table III. (page 613), for the sake of easy comparison. 
Type III. Conoidal discs. — Messrs. Henry Bamford & Sons 
exhibited three different types of mills, all of which received a 
more or less complete trial. Mill No. 3366 consists of a pair 
of vertically arranged cast-iron discs, 14£ inches diameter, of 
conoidal profile, with a reversible peripheral ring. The discs 
are of hard white iron, trued up by grinding, and are driven at 
450 revolutions per minute by strap direct. The arrangements 
for setting to grind coarse or fine, as well as for safeguarding 
the discs from the passage of hard foreign substances through 
the mill, are similar to those already described. The grist, after 
leaving the mill, is received on a jogging screen, which separates 
the coarse from the fine meal, depositing the former in a box, 
from which it is occasionally returned to the hopper by the 
attendant. The mill can be supplied without this screen at a 
proportionately lower price. This machine made good samples, 
whether in maize, beans, oats, or barley, and the work was 
expeditiously done. Reference is again made to Table III. 
for comparative particulars of draught and duty. 
Mill No. 3364 is similar to that just described, but furnished 
with a pair of rollers 8 inches diameter and 9 inches long, for 
crushing oats. One of these rollers is sparsely grooved, the 
other is smooth. They are geared together at equal speeds, 
but are not permitted to come into contact with each other. 
Adjustment is effected by a pair of set screws which force the 
bearings against stops, while the stops themselves are, very 
simply, adjustable so as to allow for wear in the rolls. The 
plan is good, and takes less power than contact crushing. 
This mill received \ cwt. of oats only, it being considered 
needless to re-experiment with the grinding discs, and made an 
excellent sample, the work being done expeditiously. 
Mill No. 3363 is similar in principle to No. 3366, but is 
