45, COENHILL, B.C., AND 122, REGENT STREET, W., LONDON. 437 



ELECTRIC LIGHT. 



FIG. 2o% 



FlG. 2591. 



IN 1801 the distinguished chemist SIR HUMPHRY DAVY first exhibited, at the Royal 

 Institution of London, a series of brilliant experiments with the Electric Light, by 

 means of a Battery of 2,000 plates, each 4 inches square ; but it was not until the 

 more permanent and powerful batteries of Daniell, Grove, and Bunsen were invented 

 that the light became of any practical use. 



As an illuminating agent for optical experiment it is invaluable ; and it has 

 been applied to Light-house service, with very considerable success, by Mr. Holmes, 

 at Dungeness on the south-east coast of England, since June, 1862. This light is 

 produced by a powerful Magneto -Electric Apparatus similar to one exhibited in 

 action by Mr. Holmes at the Exhibition of that year. 



The Apparatus we catalogue in this section is chiefly adapted for private experi- 

 ment and the lecture-room ; but by extending and enlarging the series of batteries 

 an Electric Light can be supplied of sufficient intensity to illuminate a large area, 

 for which special quotations will be given upon application giving particulars of 

 what is required. 



2591 



2592 

 2593 

 2595 



2594 A Set of o.Callan's Cast Iron Batteries, in stout wood tray 



2595 A Set of 10 ditto ditto in tray . 



A Set of 5 Grove's Batteries, in strong wood tray 



(as fig. 2591) 



A Set of 10 ditto ditto in tray .... 

 A Set of 5 Bunsen's Carbon Batteries, in stout wood tray 

 A Set of 10 ditto ditto in tray .... 



Each. 

 s. d. 



3 3 



6 6 

 2 15 

 5 5 

 2 15 

 5 10 



