Report on Implements at Preston. 
121 
corrugated sheets, with iron framing underneath. The chains 
for raising or lowering the roof are fitted with hooks ; to these 
two or three of the weights of the pressure apparatus can be 
hung as balance-weights, and the roof raised with their aid bj 
one man. The design is well worked out ; but the cost of these, 
and probably of all iron silos, must be very much against their 
use. A silo to hold 16 tons, at 50 cubic feet to the ton, costs 
17/. ; its roof and door, 7/. 10a-. ; apparatus for pressure and 
covering boards, 13?. \2s.Qd. ; making a total of 38/. 25. Qd. The 
same items for one to hold 60 tons amount to 42/., 17/. 17s. 6rf., 
and 49/. lOs., making the total 109/. 7s. 6t/. 
Pressure is obtained by fixing two pulleys on each end of the 
pressure beam and one pulley on the ground. A chain with 
one extremity anchored to the ground is then passed round the 
three pulleys, and cast-iron weights are hung upon its other 
extremity. In this way a weight of 10 cwt. at each end of the 
beam gives a pressure of 2 tons. On a silo 16 feet by 10 feet 
8 inches, with two beams, an actual pressure of 8 tons is applied, 
equal to 112 lbs. per square foot. 
I have been unable to obtain an illustration of the Silo Press 
No. 1148, exhibited by Mr. W. Shuker, but am indebted to 
Mr. F. S. Courtney, our Assistant Engineer, for the following 
description of it, and also for the illustrated description of 
Messrs. Moore and Co.'s Press. 
" Mr. W. Shuher. Silo Press, No. 1148-— On either side of the silo wall, 
and extending from top to bottom of the same, an upright pillar is securely 
attached, with a rack upon it extending for about three-fourths of the 
distance from the top. A pressure beam extends across the silo between the 
above-mentioned pillars, carrying at its centre two windlasses, and at either 
end two fulcrum castings. A chain from cither windlass is attached to the 
end of a long lever, the other end of which engages in a movable casting iu 
the upright rack pillars, the fulcrum being at the end of the pressure beam. 
Each travel of the lever gives 3 inches compression at the end of the beam, 
and a paul engaging in the rack-pillar keeps the beam down while a fresh 
purchase is being taken with the lever. By repeating this operation the 
silage is compressed firm, and in order to keep uji continuous pressure upon 
it, a wrought-iron lever, with a dog-bar engaging in the ratchet-wheel of the 
windlass, is attached. A weight of 100 lbs. on the end of this lever, gives a 
continuous pressure of 12 tons at each end of the pressure beam. When the 
pressure beams have been worked low down in the silo, they may easily be 
hoisted up to the top again by removing the main lever and attaching the 
chain from the windlass to the end of the beam, leading it over a pulley in a 
movable casting in the upiight rack jJiHars and then working the continuous- 
pressure levers. 
"Messrs. Moore & Co. Silo Tress, No. 2691. — This machine (Fig. 26, 
p. 728) consists of a vertical bar (a) fixed securely to the bottom of the silo, 
and extending to the top of the same. Two cast-iron serrated cheeks (i! k), 
about 3 feet long, are attached to the upper part of the vertical bar. The 
position of these cheeks may be varied at will, as holes are provided some 
distance down the bar, so as to allow of the subsidence of the silage. 
