SCIENCE IN RELATION TO THE ARTS. 59 



of electricity. Taking the loss of effect in all cases as 50 per cent, 

 electric transmission presents the advantage that an insulated wire 

 does the work of a pipe capable of withstanding high internal pressure, 

 which latter must be more costly to put down and to maintain. A 

 second metallic conductor is required, however, to complete the elec- 

 trical circuit, as the conducting power of the earth alone is found un- 

 reliable for passing quantity currents, owing to the effects of polariza- 

 tion ; but, as this second conductor need not be insulated, water or gas 

 pipes, railway metals, or fencing-wire, may be called into requisition 

 for the purpose. The small space occupied by the electro-motor, its 

 high working speed, and the absence of waste products, render it 

 specially available for the general distribution of power to cranes and 

 light machinery of every description. A loss of effect of 50 per cent 

 does not stand in the way of such applications, for it must be remem- 

 bered that a powerful central engine of best construction produces 

 motive-power with a consumption of two pounds of coal per horse- 

 power per hour, whereas small engines distributed over a district would 

 consume not less than five ; we thus see that there is an advantage in 

 favor of electric transmission as regards fuel, independently of the 

 saving of labor and other collateral benefits. 



To agriculture, electric transmission of power seems well adapted 

 for effecting the various operations of the farm and fields from one 

 center. Having worked such a system myself in combination with 

 electric lighting and horticulture for upward of two years, I can speak 

 with confidence of its economy, and of the facility with which the 

 work is accomplished in charge of untrained persons. 



As regards the effect of the electric light upon vegetation there is 

 little to add to what was stated in my paper read before Section A last 

 year, and ordered to be printed with the report, except that, in experi- 

 menting upon wheat, barley, oats, and other cereals sown in the open 

 air, there was a marked difference between the growth of the plants 

 influenced and those uninfluenced by the electric light. This was not 

 very apparent till toward the end of February, when, with the first 

 appearance of mild weather, the plants, under the influence of an elec- 

 tric lamp of 4,000 candle-power placed about five metres above the 

 surface, developed with extreme rapidity, so that by the end of May 

 they stood above four feet high, with the ears in full bloom, when 

 those not under its influence were under two feet in height, and showed 

 no sign of the ear. 



In the electric railway first constructed by Dr. Werner Siemens, at 

 Berlin, in 1879, electric energy was transmitted to the moving carriage 

 or train of carriages through the two rails upon which it moved, these 

 being sufficiently insulated from each other by being placed upon well- 

 creosoted cross-sleepers. At the Paris Electrical Exhibition, the cur- 

 rent was conveyed through two separate conductors making sliding or 

 rolling contact with the carriage, whereas in the electric railway now 



