Report on the Trials nf Imjilements at Cardiff. 473 
wire, terminating in the rims of two iron castings, one of which is fixed and 
the other movable upon the shaft by means of a central screw, similar to that 
i in Hornsby's screen. To secure regularity in the spaces between the main 
wires, twelve barrel springs of fine steel wire, nxnning the full length of the 
■ linder, are affixed to it by wire stitching. In the Xo. 2291 machine these 
rings are placed inside, while in No. 2292 they are placed outside the main 
cylinder. The second of these is the older, and, in the opinion of the Judges, 
the better arrangement. When the springs are outside it is necessary to leave 
three spaces in the brush frame to avoid the springs, and the brush must be 
driven by spur-wheel and pinion ; but the interior of the cylinder is a plain 
-urface, and the corn, guided throughout its passage by an Archimedian 
■ew, is always in contact with the screening surface. On the other hand, 
wiien the springs are inside they are perpetually lifting the corn, so that 
much of it falls from one spring to another, and is only partially brought 
into contact with the true screening surface. There is a simplicity in this 
arrangement that at first sight is taking, for the exterior of the cylinder being 
plain, the revolving brush is also made plain, and rotating by friction needs 
I no gearing to drive it. The trial proved that this simplicity, however, was 
obtained at the cost of efficiency, and the older form of screen was the only 
one selected for a second trial. 
Fig. 33.— W. Bainforth and Son's Adjustable Botary CornScreen, .^0.41 52. 
Xo. 4152. Hainforth and Son. — The cylinder of this screen is made of one 
entire piece of woven wire-work, with meshes that diminish in size by 
' changing from the square to the diamond shape as the cylinder is shortened. 
I Both ends of the wire net-work are fixed in the rims of iron castings. There 
i are three of these castings ; the upper one is fixed, the centre and lower one 
I sHde in slots, in the central hollow-shaft, and are moved by a central screw. 
The two ends of this screw have threads of a diflerent ])iteli, and by this 
means the meshes at the feed end of the screen are always closer than those 
at the delivery end. No springs or lapping wire are needed, and as the screen 
