Jlay and Straw Presses at Nottingham. 
581 
order. After the first trials were completed, Ladd's, and Ste- 
phenson's No. 3,819, were tried a second time upon loose hay, 
when enough had been done to permit of a decision being made 
without further experiments. 
Article No. 3,820 (Fig. 5, p. 605), exhibited by Mr. George 
Stephenson, Newark-on-Trent, was the first machine to come to 
trial in Class 2 on July 6. This, and the succeeding machines, 
were tried upon loose hay and straw, but not upon new hay, as 
in the case of the steam-power machines. Stephenson showed 
two presses in this class, characterised, one, by the employment 
of an ordinary "toggle-joint," and the other by a modification of 
this well-known device, which may be described as a " half 
toggle " (see diagram on p. 605). In it, the lower limbs of the 
ordinary toggle-joint are discarded, while the lower extremity of 
each upper limb is furnished with a roller, which travels back 
and forth upon a rail, forming part of the sole-plate of the 
machine, as the limbs are drawn together or separated. The 
press under review (No. 3,820) was a "toggle-joint" machine; 
the " half- toggle " press was tried later. 
The macliine consists of a vertical box, or press-body, closed at the top 
by a sliding door, and, laterally, by a swinging door. A platform, placed at 
such a height that stuff' can easily be received from the thrasher and forked 
through the Latter door, surrounds the press-body, and receives loose 
material. Two men were employed upon this platform, either forking or 
trampling, and one man drove the horse. 
Within the box there is a moving platten which, during the charging 
operation, forms the bottom of the press-body. The platten is supported by 
the two upper limbs of the toggle, and is low down in the box when all four 
members of the joint are widely open, high up in the box when these are 
closed. 
The toggle is operated by a chain, which, after passing around a guide 
pulley to give it direction, is wound upon a windlass actuated by the horse. 
The platten rises, quickly at first, and slowly at last, through a considerable 
space — a movement well suited, as it appears, to the pressing of hay and 
straw, where a gradually increasing pressure, ending in a powerful final 
pinch, is the thing desired. 
AVhen the toggle is open, and while there is little or no pressing to do, 
the horse's energy is used in bringing the widely separated limbs of the joint 
together, the leverage being at that moment greatly against him ; but when 
the final pinch is given, and the work of compression is hardest, there is a 
hardly appreciable leverage against the horse, qua the toggle, so that his 
work is equahsed throughout the whole movement of the platten. 
After a bale has been completed, the windlass is released by means of a 
clutch, and the platten falls by its own weight, the rapidity of its descent 
being checked by a brake on the chain-barrel, under the control of the 
attendant. The bales are tied in the usual way, either with cord or wire, 
and afterwards tumbled from the platform to the ground. 
The ratio of movement between the horse and the platten at the point 
of maximum pressure is 151 to 1, so that, estimating the pull of the hgrsq 
9,% H cwt., this would give 11'3 tons pressure upon the platten, 
