168 president's address SECTION H. 



curiosity on photographs of the assemblage of shafts and strings 

 now considered a necessary part of the equipment of a machine shop. 



The advantages which the electric system possesses over its rival 

 are numerous ; not the least being the fact that an idle machine 

 absorbs no power, there being no lengths of shafting and accom- 

 panying belting to be kept in motion, whether the whole or a single 

 machine of the group is employed. That electric-driving has passed 

 the stage of experiment is evident when we find that Messrs. 

 Siemens are in their own work steadily doing aw^ay with the many 

 independent engines they once possessed, concentrating the pro- 

 duction of motive power, and distributing it electrically to the 

 various shops, the machines therein being driven either individually 

 or in groups, according to the nature of the work on which they 

 are employed. 



Messrs. Siemens inform me that a considerable econ my in fuel, 

 wages, and upkeep has already been effected, and that they propose 

 to complete the application of this system. Messrs Easton and 

 Anderson have for the past five years been driving electrically tw^o 

 overhead travelling cranes, one a t20-ton crane of 40ft. span, in 

 which a single five-unit motor running continually effects the 

 necessary movements through the medium of spare gearing. The 

 current is conveyed to this crane by an angle iron supported on wood 

 blocks and running along the shop wall. One face is ground up 

 bright, and contact made by a sliding!spring. The retiirn is through 

 the rails. The second crane is of 15 tons capacity, and has a 

 separate motor for each motion, which is stopped, started, or 

 reversed, as required, the current being collected and returned by 

 means of overhead wires. So satisfactory has been the performance 

 of these cranes and of other electrically-driven machines that 

 Messrs. Easton & Anderson contemplate a complete re-arrangement 

 of their driving plant, substituting for indejiendent prime movers 

 a central generating station with triple-expansion engines, from 

 which power will be electrically distributed throughout their work- 

 shops. The Northern Railway of France find that, at a small 

 repairing shop, substituting electric power at fkl. per B.T.U.. with 

 a separate motor to each machine, has effected an economy of 50 

 per cent, (all charges and depreciation included) as compared with 

 the cost of the previous ariangement of gas-engine and belting. In 

 mining operations hand labor is being rapidly replaced by power. 

 Coal-cutting machines have eflTected a saving of about 15 per cent, 

 of the coal vein otherwise wasted in the form of fine coal and dust. 

 The coal is obtained in more solid and larger blocks, whilst the cost 

 of production has been reduced by from 20 per cent, to 30 per 

 cent, as compared with hand labor. 



The transmission of power underground has been accomplished 

 by the use of compressed air, hydraulic pressure, and wire ropes — 

 the efficiency of such methods being fi-om 30 per cent, to 40 per 

 cent. By the adoption of electricity, however, the efficiency of 



