NATURE 



145 



THURSDAY, JUNE 12, 1890. 



ELECTRIC VERSUS GAS LIGHTING. 

 UEclairage Electrique actuel dans Diff&ents Pays. By 

 Jules Couture. (Paris : J. Michelet, 1890.) 



IN this, the second edition of this pamphlet, a com- 

 parison is made between the prices of lighting by 

 electricity and gas at Milan, Rome, Paris, Tours, Manosque, 

 Perpignan, Marseilles, and New York. In Milan, the 

 electric energy is either charged for by a fixed rate per 

 lamp per year, plus a payment for each hour during 

 which the lamp is turned on (the fixed annual rate and 

 the hourly payment depending on whether the lamps be 

 of 10 or of 16 candles), or the payment may be made to 

 depend entirely on the consumption. In the latter case, 

 however, the hourly payment per lamp diminishes with 

 the number of lamps employed in the building, the rate 

 per hour varying from 6 centimes for a lo-candle lamp 

 if there be not more than 40 lamps, to 3^ centimes per 

 lo-candle lamp if the number exceed 151. The incan- 

 descent lamps at Milan appear to require 6 watts per 

 candle, and are therefore evidently specimens of the old 

 Edison lamp ; at the present day, however, there are 

 lamps that can be incandesced with 40 per cent, less 

 power, and still have a long life. In comparing the price 

 of lighting by electricity and gas, M. Couture assumes 

 that one Bengel gas-burner consuming 105 litres of gasper 

 hour gives 10 candles. This is equivalent to 5'9 cubic 

 feet per hour for 16 candles. Now a good Argand burner 

 with London gas will give 16 candles for a consumption 

 of 5 cubic feet per hour, whereas a common burner will 

 not give more than 5 or 8 candles. M. Couture's typical 

 burner and the Milan gas must therefore be good, where- 

 as, as already mentioned, the incandescent lamps em- 

 ployed in Milan must be of an old character. Neverthe- 

 less, since electric lighting is supplied at 9 centimes per 

 hour for a i6-candle lamp, and at 5 '6 centimes (or about 

 one halfpenny) in buildings using many lamps, the Milan 

 Gas Company thought it wise to drop their price from 

 36 to 25 centimes per cubic metre of gas in the regions of 

 the town supplied with electricity. For the benefit of 

 readers who may study the copious information contained 

 in this French treatise, we may mention that the London 

 price of is. 6d. per 1000 cubic feet of gas is equivalent to 

 almost exactly one penny per cubic metre. 



In Rome, the Anglo-Roman Gas Company have utilized 

 alternate-current transformers to distribute electric energy 

 throughout the town from an electric station with 2700 

 horse-power, constructed on their own grounds, and have 

 thus avoided the erection of expensive central stations in 

 the town itself. The price charged is 8 centimes per hour 

 for a i6-candle glow-lamp, and this M. Couture regards 

 as a very remunerative one. It represents about 2\ times 

 the cost in Rome of lighting with improved i6-candle 

 Wenham gas-burners. M. Couture speaks of the two 

 dynamos employed there as being the largest in the 

 world, but, as they are only of some 500 horse-power each, 

 it is clear that the author has not heard of the dynamos 

 at Deptford, one of which has been running for some time, 

 and which produces 1 500 horse-power. Indeed, M. Couture 

 is wonderfully silent about the electric lighting of towns 

 NO. 1076, VOL. 42] 



in England, and makes no reference whatever to the 

 prices charged for electric energy at various places in this 

 country, or to the regulation of these prices by the 

 systematic action of the Board of Trade. 



Various installations employing transformers are re- 

 ferred to, amongst others that at Tours, and it is men- 

 tioned that the new price charged there for electric energy 

 is only about 30 per cent, more than for an equivalent 

 amount of gas. The only reference to electric light- 

 ing in Great Britain is to the first use of transformers 

 when the Metropolitan Railway stations at " Edgard 

 Road" and "Olgate" were experimentally lighted in 

 1883 ; and of the large amount of electric lighting work 

 that has been carried out on the Continent by English 

 engineers nothing is said, if we except the statement that 

 " Badkok " and Wilcox boilers are used at Marseilles and 

 at other towns. The value of the book, which is consider- 

 able, would have been increased if some reference had 

 been made to " Sir Siemens " and " Sir Crompton," since 

 certain lirge towns abroad, not mentioned in this book . 

 owe their electric lighting to the exertions of these firms. 



Formerly, electrical companies maintained installations 

 at a loss, for the sake of advertisement : while gas com- 

 panies, to avoid losing the streets that were lighted, have 

 continued the lighting for a return less than the cost 

 price. The financial results of electric supply companies 

 have often not been sufficiently prosperous to enable 

 interest to be paid upon the capital invested, but the 

 same may be said of many gas companies in the early 

 days of their existence. At Dijon, a central electric sta- 

 tion has been rendered commercially impossible by the 

 Gas Company dropping their price from 45 to 25 centi- 

 metres per cubic metre when they heard that the erection 

 of one was contemplated. 



The Marseilles Gas Company was the first gas com- 

 pany to establish a central station for the purpose of 

 ascertaining the conditions under which the new method 

 of lighting could be advantageously used in conjunction 

 with gas and oil. Since 1 881, when the Marseilles Gas 

 Company first took up electric lighting, they have gradu- 

 ally extended their operations, so that to-day the electric 

 lighting of the town is considerable. At the rates 

 charged, it is 20 per cent, dearer to obtain 10 candles 

 for 1000 hours in the year by electricity than with a. good 

 gas-burner ; but if the time of lighting be extended to 

 2000 hours, electric lighting is only 6 per cent, dearer 

 than gas lighting, and in the case of a 10-candle lamp 

 lighted for 3000 hours in the year, electricity and gas 

 come out equal in price. Consequently, if the gas be 

 burnt in common burners, or if governors be not em- 

 ployed to keep the pressure of the gas constant, lighting 

 with gas will actually be dearer in Marseilles than by 

 means of electric glow-lamps. However, as the author 

 points out, it is very important to see that a lo-candle 

 glow-lamp really gives an illumination of 10 candles, since 

 it is by the lamp, and not by the light, that the charge is 

 made. 



Electricity is, of course, now being much used where 

 gas was formerly employed, but an interesting example is 

 given in this book of electricity being resorted to for the 

 lighting of a town in which gas could not be adopted. 

 Manosque, in the Basses Alps, was lighted, up to 1888, 

 with oil, the municipality not being able to introduce gas, 



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