SCIENCE. 



5 



ELECTRICITY AS POWER. 



BY FRANCIS P. UPTON, ESQ. 



In the early history of electrical science, many forms 

 of engines were made, by which the power of elec- 

 tricity could be shown. Each was as wonderful as the 

 other to the unthinking observer; for, without appar- 

 ent combustion of fuel, work was done. We find, 

 among the largest of these engines, one used in St. 

 Petersburg, to drive a small boat, and one in this 

 country to propel a train. 



The United States Congress voted a sum of money 

 to Prof. Page to carry on his experiments and he 

 built a very efficient motor. After many experiments, 

 though it was found that any amount of power could 

 be obtained, yet the expense was so great as to make 

 it of no practical value. In a small machine, the con- 

 sumption of zinc might not be noticed, while in a 

 large machine it would be found to burn exactly as the 

 work was taken. Now that the doctrine of energy is 

 clearly understood, the folly of the attempt can easily 

 be seen. In a battery the fires are fed with an ex- 

 pensive metal. The energy developed by the zinc, 

 thus used, was given to it artificially when it was re- 

 duced from the ore. In order to obtain a convenient 

 fuel, both the coal and zinc ore must be mined, and 

 the latter reduced, absorbing in the reduction a very 

 small per cent, of the energy of the coal used in the 

 process. Thus batteries for furnishing power consume 

 a fuel at least fifty times more expensive than coal. 



Besides the cost of fuel, the atmosphere, so to 

 speak, in which the zinc burns, must be furnished to 

 it artificially in the shape of acids or solutions. Though 

 this has nothing to do with the theoretical cost, yet 

 in practice, it is found to be the largest item of ex- 

 pense. It resembles furnishing a boiler with air made 

 by a chemical process, so far as the economy of com- 

 bustion is concerned. Yet the convenience and relia- 

 bility of a battery to burn zinc has, where very small 

 amounts of power are required, allowed of its use 

 commercially, since steam is extremely difficult to 

 manage in fractions of a horse power. 



To-day the practice has been entirely reversed from 

 what the first experimenters expected to realize. For 

 electricity is now entirely made by means of steam 

 engines to drive large motors. The last few years 

 have brought the means of generating and using elec- 

 trical currents to such a high state of perfection that 

 power may be with economy transferred by them. 



The loss in transferring is double ; if a machine 

 converts fifty per cent, of the power it receives from a 

 staem engine, only fifty per cent, of that can be util- 

 ized, that is, twenty-five per cent of the original ; thus 

 wasting seventy-five parts out of each hundred of 

 energy. A sixty per cent, machine can render effective 

 thirty-six per cent. ; an eighty per cent, machine can 

 turn into useful work sixty- four per cent, and so on. 

 This wasting of power in the transmission is more than 

 counterbalanced in a great many cases by its de- 

 livery at the point where needed; for example, from a 

 waterfall to a field for ploughing and threshing, as has 

 been done in France; or from the shore to the water 

 for the purpose of driving a torpedo boat, as has 

 been done in this country. 



Lately experiments have been made to show 

 the application of electricity to railroads. Mr. 



Siemens, in Berlin, and Mr. Edison, at Menlo Park, 

 are experimenting with electrical railroads. Mr. Edi- 

 son uses the rails as conductors of electricity, the cur- 

 rent going in one and returning in the other. The 

 wheels are insulated, so that, by means of brushes on 

 them, the electricity may be brought to the moter, 

 which is on a carriage. The moter is simply one of 

 Mr. Edison's generating machines, laid on its side, 

 and connected by suitable mechanism to the axle of 

 the driving wheels. On an experimental track of 

 one-half mile length, a speed of twenty to thirty miles 

 an hour has easily been reached, in spite of heavy 

 grades and sharp curves. 



For elevated and underground railroads, this method 

 has many advantages ; it does away with all the smoke 

 and noise from the puffing of the locomotive, and 

 substitutes for the many locomotives a few stationary 

 engines scattered along the route. Mr. Edison feels 

 very confident of success, since his troubles so far 

 have all been in transferring the power from the arma- 

 ture to the driving wheels. He thinks that if the 

 armature is only reliable, experiment will lead to 

 proper mechanical devices for transferring the power 

 from the quick -running armature to the slower driving 

 wheels. 



The road will be very useful in mountainous regions, 

 since the engine is quite light and can be carried by 

 trestle work and light earth work, over any country. 

 The engine and boilers are not in this case put on 

 wheels and required to push themselves over grades 

 and around curves, but are placed in the valley below. 

 Perhaps in many cases they may be done away with 

 and water used to drive the generators. 



For beach roads, in grand exhibitions, as feeders to 

 main lines, and in many ways it is easy to see that 

 use may be made of a properly constructed road. 

 The gentle fluid, which has so quietly, for many years 

 been the swift messenger of man, is now showing that 

 it is also able to be a strong and lusty servant, and 

 carry any load that it may be asked to take. 



Electrical Insects. — It is not generally known that there 

 are insects which possess the peculiar electrical properties 

 of the Raia Torpedo and Gymnotus Electricus. Kirby and 

 Spence, in their entomology, describe the Reduvius Serratus, 

 commonly known in the West Indies by the name of the 

 wheel bug, as an insect which can communicate an electric 

 shock to the person whose flesh it touches. The late Major- 

 General Davis of the Royal Artillery, well-known as a most 

 accurate observer of nature, and an indefatigable collector of 

 her treasures, as well as a most admirable painter of them, 

 once informed me, that, when abroad, having taken up this 

 animal and placed it upon his hand, it gave him a consider- 

 able shock, with its legs, as if from an electric jar, which he 

 felt as high as his shoulder, and dropping the creature, he 

 observed six marks upon his hand where the six feet had 

 stood. Two similar instances of effects upon the human 

 system resembling electric shocks, produced by insects, have 

 been communicated to the Entomological Society by Mr. 

 Yarrell ; one mentioned in a letter from Lady de Grey, of 

 Groby, in which the shock was caused by a beetle, one of the 

 common Elateridae, and extended from the hand to the 

 elbow on suddenly touching the insect ; the other caused by 

 a large hairy lepiclopterous caterpiller, picked up in South 

 America by Capt. Blakeney, R. N., who felt on touching it 

 a sensation extending up his arm, similar to an electric 

 shock, of such force that he lost the use of his arm for a 

 time, and his life was even considered in danger by his medi- 

 cal attendant. 



