EDITOR'S TABLE. 



235 



When scientific men shook their heads 

 and said it would not do — that there 

 "were limits in the case which forbade 

 the expected progress, and tliat zinc 

 burned in batteries could not com- 

 pete with coal burned under the boil- 

 er — the replies were ready. First, did 

 not Dr. Lardner say that steam-navi- 

 gation across the Atlantic Avas imprac- 

 ticable? Second, was there any limit 

 to that power of which the lightning- 

 flash was an example? Third, if the 

 electro-magnetic engine was weak, was 

 it not also new, and who would pre- 

 sume to put restrictions upon man's 

 inventive genius, especially when the 

 main thing was already achieved, and 

 nothing remained but to work out the 

 minor improvements? The new mo- 

 tor, however, could not be made to 

 work, and so hopes were crushed, in- 

 vestments lost, and the excitement died 

 away. 



The difficulty with the electric light, 

 which has hitherto defied resolution, 

 notwithstanding the efforts of experi- 

 menters for a generation, is that it can 

 only be realized under an intensity of 

 action that becomes far too expensive 

 for common use, where only a small 

 amount of illumination is required, A 

 brilliant light can be got from the elec- 

 tric current by the incandescence of 

 carbon or metallic particles, which will 

 flood great spaces with a vivid illu- 

 mination much cheaper than can be 

 done in any other way, but nobody has 

 yet been able to divide and distribute 

 this intense light so as to utilize it in 

 small amounts wherever wanted, at a 

 cost that can compete with the ordi- 

 nary sources of illumination. A well- 

 informed writer in a late issue of the 

 Kew York Sun gives the following in- 

 structive presentation of the present as- 

 pect of the subject : 



"I judge that tho panic in gas-stocks, 

 which has been produced in great part by 

 the broad claims of Mr. Edison to the dis- 

 covery of a practicable method of subdivid- 

 ing the electric light, is, to say the least, 

 premature. Mr. Edison is now experiment- 



ing with his light, and at latest accounts 

 had not solved all the problems involved. 

 The field in which he is laboring is an en- 

 tirely now one to liim, as the science of mag- 

 neto- or dynamo-electricity is far diflerent 

 from that of telegraphy or electro-magnet- 

 ism. There are problems involved, espe- 

 cially in the subdivision of the light, which 

 are far greater than any embodied in any 

 previous invention or improvement of Mr. 

 Edison. The scientific world has been la- 

 boring at it almost constantly sin«e King's 

 invention in 1848. In 1858 M. Jobart, of 

 Paris, made some very startling claims, 

 which were almost exactly the same as 

 those made by Edison, but continued ex- 

 periment exposed their fallacy. 



" The principal difficulty to be overcome 

 is the lack of economy in any method of 

 producing light by electricity, except by tho 

 voltaic arc between carbon-points, and as 

 Mr. Edison disclaims this method, and lim- 

 its himself to the plan of incandescence, he 

 will find his path beset with difficulties in 

 this direction. This is shown by the well- 

 known fact that an electi'ical current of a 

 given strength will yield about ten times as 

 much light when used to produce the voltaic 

 arc between carbon-points as it could by be- 

 ing passed through a piece of platinum, bo 

 as to raise it to a white heat and give the 

 light. In some experiments recently made 

 in Paris by M. Fontaine, it was found that 

 a powerful battery of forty-eight elements 

 would produce in one lamp a light by in- 

 candescence equal to forty burners ; but 

 that, when the same current was used in two 

 lamps, the light in each was only three to 

 five burners, and, when divided between 

 three lamps, only one-quarter burner in 

 each. Further subdivision resulted in a 

 total extinction of tlie light. A similar re- 

 sult was reached whether the lamps were 

 placed in series in the same circuit or in de- 

 rived circuits. In using a dynamo-electric 

 machine in place of a battery as the source 

 of the electricity, the same difficulty would 

 present itself, with this additional one, that 

 whereas the electro-motive force of a battery 

 remains constant under all changes of resist- 

 ance, that of a machine does not, but de- 

 creases as the resistance increases. 



" The writer has thoroughly investigated 

 the subject of electric light as an economical 

 subtitute for gas, and is entirely familiar 

 with all that has been accomplished here or 

 abroad in this direction. Abroad, by means 

 of the Gramme machine and the JablochkoflT 

 candle, sixteen lights of VOO-candlo power 

 each are produced from one machine, ab- 



