Report on the Trials of Implements at Cardiff. 469 
one quart over a No. 8 hand-screen, and noting the inferior com 
thus extracted. Two of the machines were provided with stone 
separators, but their efficiency in this respect was not put to the 
test, as the com used in the trial was free from stones. 
Nos. 3731 and 3734:. B. Bohy. — These two machines only differed in two 
r :sr ects, the first and higher-priced one is much larger than the other, but was not 
r. -r: with the stone separator shown at the upper end of the screen in Fig. 31. 
Tiie spur-wheel on the shaft that carries the handle drives the pinion l3elow it. 
This pinion is keved upon a crank shatt, and, by means of the forked con- 
necting-rod fastened to the upper side of the screen, it gives a backward and 
forward movement to the screen, which thus slips up and down with a quick 
movement upon tha chilled-steel slides which support it on the frame. The 
wires of the screen are ke[)t clean by the action of six rows of cleaning collars, 
strung upon transverse iron rods that are fixed upon the frame-bed. ITie 
screen itself is composed of stout strained wires, placed horizontally upon bars, 
in notches ptmched by machine. The shape of these wires has recently 
been modified on the suggestion of one of the firm of Messrs. Ba.ss and Co. 
After long tisage, the sides of the rotmd wires became worn, so that they had 
Fig. 31. — Bobya New Patent Self-cleaning Com Screen, No. 3734, vnth 
removable Wire Part. 
an oval in~t.-au u. a i.i.c...j.x i-.ci.^Q; the spaces between tbem being ihris 
enlaiged, it was necessary to reset the wires : the flattened wires, when once 
rfrset, presented a deeper wearing surface to the grain tailing through them, and 
th-e spaces remained of the right size for a much longer time than when new 
wires were used. This observation has induced the manufacturers to use in the 
first instance wires with flattened sides, and the screen is now much mere 
linrable than it was. Another improvement has been made by arranging the 
screen and iron frame upon which it nms in such a way that the screen { art 
can be lifted out and another of coarser or finer gauge fixed in its piace. A 
silding board at the bottom of the hopper regulates the feed space ; he corn 
