ARTIFICIAL LIGHTS 9 



tricity fiom forty or more Grove or Bunsen cells to pro- 

 duce this light, and there is then needed a special kind 

 of lamp furnished with some mechanism that will auto- 

 matically keep the two carbon points at a proper height 

 and a certain distance apart. Such lamps have been 

 devised by Dubosque of Paris, and Browning of Lon- 

 don, and others ; but the best of them are not constant, 

 except with a very powerful battery, and when used 

 with only forty or fifty cells will need personal attention 

 every few minutes. Browning has advertised a small 

 electric lamp, which he says will give a constant light 

 with only six or eight cells. A number of these small 

 lamps have been brought to this country, but, so far as 

 the writer knows, no one has been able to work them 

 with anything like so small a battery. 



There are several reasons why the electric light is 

 not more generally used for this and other purposes. 

 First, its cost: the battery with lamps costing about 

 two hundred dollars. Second, the consumption of zinc, 

 acids, and mercury for amalgamation, which, with the 

 labor of setting it up and cleaning it after use, may 

 be reckoned at ten dollars a day. Third, the noxious 

 fumes which constantly arise from a working battery, 

 making it necessary to have a special battery-room, well 

 ventilated; and fourth, the need of frequently over- 

 hauling it, re-amalgamating the zincs and filing the wire 

 connections. These have made every one who has ever 

 worked with a battery, wish that some substitute could 

 be found for it. The magneto-electric machines de- 

 vised by Wilde, Ladd, Farmer, and others, have been 

 more or less successful, but have been much too costly, 

 and require eight to ten horse-power to run them. 



The machine that promises the most for us now is 

 the one known as the Gramme machine, a French in- 



