430 



NEGRETTI AND ZAMBRA, HOLBORff VIADUCT, E.G., 



FlG. 2529. 



Fl(J. 2534. 



FIG. 2530. 



2529 Smee's Batteries, in round Stoneware Pots, so arranged with brass clamps 



that the zincs can be easily removed for cleaning and amalgamating, and 



replaced (fig. 2529) 



-pt. 5s. 6d. 1-pt. 8s. 6d. 2-pts. 11s. 6d. 3-pts. 14s. 



Smee's Batteries are constructed with one ;plate of thin Platinized Silver, and two plates of 

 Amalgamated Zinc. For charging Smee's Batteries one part by measure of strong Sulphuric Acid, to 10 

 or 12 parts of Water, will be found sufficient for slow and gentle action ; for more powerful results, 1 part 

 acid to 8 of water should be used. It should be noted that in making dilute sulphuric acid the strong acid 

 should be poured into the water slowly and gradually. 



The superiority and convenience of this Battery over all others consists in the little trouble required 

 to put it in action, and the great power obtained. They are not obnoxious or disagreeable during their 

 action, hydrogen only being evolved. One Battery with a piece of platinized silver two inches square, 

 immersed in a tumbler of dilute acid, in]connection with an electro-magnet, will support three hundred- 

 weight. 



Each. Each. 



s. d. s. d. 



2530 Smee's Batteries, in flat Glass Cells (fig. 2530) . . 12 6 15 6 

 Set of Six Half-pint Smee's Batteries, in round pots, 



and a mahogany tray ....... 1 18 6 



This set is so arranged, that it can be used for quantity or intensity effects, will show all the 

 leading facts connected with galvanism, decomposing water, deflagrating metals, &c., &c., and is well 

 adapted for the instruction of a small class. Smee's Batteries arranged in an intensity series, and 

 excited with exceedingly weak acid, answer well for ringing signal bells or short telegraph lines, care 

 being taken to keep the zinc plates well amalgamated. 



2531 Set of Six one-pint Smee's Batteries, in flat Stoneware 



cells and mahogany tray (fig. 2531) .... 330 



2532 Set of Six two -pint ditto, in ditto 440 



2533 Set of Six one-pint ditto, in flat cells and mahogany 



tray, with counterpoise weights, or ratchet wheel, for 



suspending the battery when not in use . . . 3 15 550 



2534 Smee's Batteries, Intensity Series (fig. 2534) . 550 



See also Sections Electric Light and Telegraph. 



Grove's Batteries, the elements consist of a double plate of amalgamated Zinc, and a single 

 plate of Platinum ; a porous cell separates the metals ; the former being excited by Sulphuric acid and Water 

 (1 part strong sulphuric acid to 8 parts of water), the latter by concentrated Nitric acid. This is the 

 most powerful of all voltaic arrangements, and is the best adapted for brilliant and showy experiments in 

 public institutions, or where a powerful current is required. The action is very uniform for some con- 

 siderable period. A De la Rive's Battery is a modification of Grove's, the Nitric acid being on the exterior 

 in a large glass bottle. A porous cell or tube containing the Zinc and dilute Sulphuric Acid is inserted into 

 the bottle ; this is removed out of the glass bottle (containing the Nitric Acid, and replaced by a Glass 

 stopper when the Battery is not in use ; by this arrangement a large quantity of Acid can be retained 

 ready for iise without the escape of acid fumes. 



