418 Report on the Trials of Implements at Cardiff. 
by the Society, with the addition of 201. offered by the makers, 
failed to secure the detection of the perpetrator ; but, whatever 
may have been his motive, it was defeated, as another trial 
was given as soon as the screen could be repaired. The results 
of this run are given in Table II. The screen was one of 
Rainforth's make, and the fact that, though only roughly 
knocked out into shape, it did its work perfectly in three subse- 
quent runs, is an evidence of good construction, that may ex- 
plain its popularity among the makers of threshing-machines 
Column 11 shows us that 4 out of the 15 machines tried were 
fitted with Penney 's screen, 3 with Nalder's, 3 with Rainforth's 
1 with Ransomes', and 1 with Tuxford's ; the other 3 machines 
failed to separate the corn properly. The points for perfection of 
finishing (column 41) for the machines fitted with Penney 's screen 
were respectively 5, 20, 6, and 0, giving an average of 7^ ; for 
3 fitted with Nalder's screen, 15, 10 and 5, giving an average of 
10 ; for 3 fitted with Rainforth's screen, 10, 0, and 20, giving 
an average of 10; for 1 fitted with Ransomes' screen, 12; for 
1 fitted with Tuxford's screen, 10. The performance of a rotary 
screen depends as much on the regularity of its revolution as 
upon its fitness of construction : the revolution of the screen is 
affected by the revolution of the drum, and this, again, depends 
upon the regularity of the feeding and the weight of the drum 
hence it is that we see so much difference in the performance of 
the same screen when used in different machines. Since Penney's 
and Rainforth's screens were entered bv the makers as hand 
worked screens for trial in Class VIII., it will be convenient to defer 
a notice of their construction till we report upon the trials in that 
class. The screens made bv Nalder, Ransomes, and Tuxford 
were not tried in Class VIII., but are noticed in the brief 
<lescription of the threshing-machines made by each of these 
firms. 
In the second run Messrs. Ransomes' stand 1st, Clayton's 2nd 
Marshall's 3rd, and Ruston's 4th ; but, adding together the points 
in the 1st and 2nd runs, the order will be 
Points. 
Clayton 1st with 832 
Ransomes 2nd 825 
Marshall 3rd „ 811 
Ruston 4th „ 783 
Each of these four machines on Saturday was submitted to i 
further trial with 15 cwts. of loose barley, an indifferent crop, witl 
short straw, rather less than 18 inches long, and 10 cwts. of blacl 
Tartary oats, short in the straw, and apparently badly harvested 
being rather cold and tough (see Table III.). In threshing th' 
barley the first three machines obtained very nearly the same total 0 
