696 INDUSTRIAL APPLICATIONS. 



and the disposable energy 



619,600 x 2". 



= 3035 kgm. 



437 x 9' Sl 



Hence 89 kilos, are necessary for a horse-power-hour. The weight 

 of lead which enters into the action is then a fraction of the total 

 weight equal to 



14,179 



= 0-03 nearly. 



467,000 



If we assume that the lead is two-thirds of the weight of the 

 couple, we conclude that the kilogramme of lead absorbs 21,269 

 coulombs. 



Plant^ arrived at much higher numbers at 36,000, and even 

 61,765 coulombs per kilogramme of lead, which corresponds to 

 0*08 or 0*14 of the total weight, or 30*65 kilos, of accumulator per 

 horse-power-hour. 



We have scarcely any practical data as to the work which can 

 be produced by a Bunsen's battery. According to M. Duboscq, 

 who has had much experience in this direction, it is possible with 

 100 elements to maintain a good arc for 15 hours, using 50 couples 

 for the first third of the time, 50 others during the second third, 

 and 100 couples in two series of 50 as a battery in the last third. 



If the light is 80 carcels, the energy expended in the lamp is 

 76*45 x 0*8 x 15 x 3600 = 3,300,000 kilogrammetres. As each couple 

 weighs 6 kilos., the useful energy for a kilogramme of battery is 



3,300,000 



The work of the battery would correspond to a horse-power-hour 

 for 49 kilogrammes. The zinc dissolved, apart from local action, is 

 a fraction of the w r hole weight equal to 



55 



= 0-0 1 nearly. 



537.000 



1252, Another property of the accumulator is to restore the 

 greatest possible quantity of the electrical energy which it has 



