468 Report on the Trials of Implements at Cardiff. 
separation desired. The strength and direction of the blast is regulated by a 
simple and ingenious arrangement of hinged boards. 
The awards in this class were as follows : — 
Corn-dressing MucJmies. — J. Cooch, Harlestone, Northamptonshire : First 
Prize, 151. Thomas Baker, Compton, Newbury : Second Prize, 10?. W. N. 
Nicholson and Son, Newark, Notts : Third Prize, 5/. W. Rainforth and Son, 
Brayford Head, Ijincoln : Highly Commended. Corbet and Chipchase, Shrews- 
bury : Commended. John Baker, Wisbeach : Commended. 
Class VIII. — Corn-Sceeens. 
The very general adoption of finishing threshing-machines 
has greatly increased the demand for rotary screens as a part of 
the machine, but has made it less necessary for each farm to 
be provided with its own hand-worked screen. As a separate 
machine, the screen is now perhaps of greater value to the 
maltster and miller than to the farmer; but the latter still finds 
it often serviceable, and must always be interested in trials that 
test the qualities of a screen more perfectly than when it is tried 
merely as a part of the complex operation of threshing and 
dressing corn. 
The nine machines tried were entered by six exhibitors, and 
may be divided into two classes — the plane and the rotary. The 
first and older form is represented by four machines, three of 
them entered by Mr. R. Boby, and one by Mr. T. Corbett. The 
corn in these screens is delivered spread over the upper part of 
a plane, more or less inclined, and formed of wire-net, or of stout 
longitudinal wires, fastened at their extremities and supported 
upon cross-bars. 
In the five rotary screens the corn in each case is delivered 
into one end of a revolving wire cylinder, slightly inclined ; its 
descent is regulated in Coleman and Morton's machine by the 
peculiar shape of the wires, and in the other four machines by an 
Archimedean screw of sheet-iron, which prevents the too rapid 
descent of the grain, and distributes it evenly over the surface. 
The machines in this class were tried in the same way as the 
corn-dressing machines ; they were first driven by a hand-power 
machine, and tested by dynamometer, and next tried without the 
dynamometer, and worked in the ordinary way by the exhibitors' 
men. Out of the nine machines tried in the first run, six were 
selected for three further trials ; these six machines comprised 
one by each of the exhibitors. l.'iO lbs. of wheat were used for each 
of the first three trials, and 100 lbs. of barley for the fourth. In 
the second, third, and fourth trials, half a bushel of corn was run 
through as a preliminary for adjusting the machines. Samples 
were taken of the head and tail corn from each run for subsequent 
examination. Th<; head-forn was further tested by passing 
