THE WAREHOUSING OF GRAIN. 139 



ing Company, Chester. The longitudinal bands are driven 

 by large pullies, and each engine has a heavy fly-wheel, 

 and governors are also being provided. 



The jiggers or hoists consist of a cylinder and ram, 5 

 inches diameter and 8 feet 6 inches stroke, with sheaves 

 multiplying ten times. They have two barrels, and are 

 made so that while one wire rope is ascending the other is 

 descending. These jiggers are examples of the best appli- 

 cation of hydraulic power, a high efficiency being attained. 



To obtain rotary motion by means of hydraulic pressure 

 entails a considerable amount of waste, the efficiency of the 

 hydraulic engines being only about 50 per cent, of the 

 power supplied. Each of the band-engines indicates about 

 four horse power, and each of the engines for driving an 

 elevator and cross-band about 17 horse power. To raise 75 

 tons of grain per hour to the height required and convey it 

 along a cross band takes about 12 horse power, without 

 making any allowance for friction. 



Were the machines at the granary in constant use, steam- 

 power would be much cheaper, but being intermittent in 

 their action, hydraulic power is more convenient and does 

 away with shafting, driving belts, etc. In addition, steam 

 power would require to have been taken from a distance, as 

 there is no place near suitable for the erection of an engine 

 or a boiler house. There are various objections to the use 

 of gas engines, such as dust, space occupied, etc. In addi- 

 tion, they would not have been suitable for the capstans. 

 Great objection would have been taken by the Insurance 

 Companies, which would have charged an extra premium 

 for the additional risk. With hydraulic pressure, on the 

 other hand, the risk of fire is greatly diminished, as the 

 pressure water can be used for the extinction of fires. In 

 the event of fire the water would be pumped at a pressure 



