45, CORNHILL, B.C., AND 122, REGENT STREET, W., LONDON. 483 



BICHROMATE BOTTLE BATTERY. 



One of the most elegant and convenient forms of galvanic battery yet intro- 

 duced is that shown in our engraving (fig. 2551) ; it is a modification of Dr. Leeson's 

 Bichromate Battery ; the elements are two plates of Graphite or Gas Carbon, and a 

 stout plate of Zinc. The exciting fluid is a saturated solution of Bichromate of 

 Potass (about 2 ounces of bichromate potass to 1 pint of water), with one part by 

 measure of strong Sulphuric Acid to every twelve parts of bichromate solution 

 (nearly two fluid ounces of acid to an imperial pint, or twenty ounces). This acid 

 should be added to the bichromate slowly : when the solution is cold, it is ready for 

 use. It will be seen from the drawing that the glass bottle-shaped cell has a long 

 neck. This is contrived for the purpose of withdrawing the zinc element from the 

 exciting fluid when the battery is not in use, and thus stopping all action or waste. 

 This zinc plate is placed between the two carbon plates, and is only half their 

 length, by a stout wire rod attached to it ; the zinc can be withdrawn from or 

 immersed in the exciting fluid very conveniently, and rapidly sets in action any 

 apparatus connected with it, such as an induction coil, a signal bell, or small 

 telegraphic instrument. Its simplicity, combined with the absence of any fumes or 

 smell, render the Bichromate Battery most useful for short action. The Bichromate 

 Batteries may be combined either for quantity or intensity effects. 



2551 Bichromate Bottle Batteries (fig. 2551). 



Price, each . . 1-pt. 2-pts. 4-pts. 



10s. 18s. 6d. 32s. 



2552 Bichromate Battery, in round Cell Quart Size (fig. 2552) - . . 16 



2553 Fuller's Constant Battery, consists of a Plate of Carbon in an Earthenware 



Cell, and a Porous Tube in which is placed a Cylinder of Zinc, the lower 

 part being surrounded with Mercury. This Porous Cell is filled with Dilute 

 Sulphuric Acid, 1 part Acid to 8 of Water. The outer Cell is charged 

 with a Solution of Bichromate of Potass with one-fourth its bulk of 

 Sulphuric Acid. Per Cell 086 



2554 The Leclanche Battery. The elements in this battery are a cylinder of 



Carbon, inserted into a round porous tube, closely surrounded by a mixture 

 of small fragments of very pure Peroxide of Manganese and Coke. The 

 top of the mixture in the porous pot is covered with wax. The porous cell 

 and its contents are placed in a glass bottle, as seen in fig 2554, with a rod 

 of Zinc (the Electro Positive element) ; and this glass cell is to be about 

 half -filled with a solution of Chloro- hydrate of Ammonia (the Sal Ammoniac 

 of commerce). 



The Electromotive force of the Leclanche Cell is stated by Ganottobe 

 -j~j that of a Daniell's Cell, and its resistance about 1^ of a British Association 

 Unit. For durability and cleanliness the Leclanche Cells are unequalled, 

 requiring but a minimum of attention, whilst on the other hand, for cost 

 of working they are the cheapest form of battery that is made, no local 

 action taking place when not in actual use. They may therefore be 

 specially recommended for all classes of intermittent work : the consump- 

 tion of material being in direct proportion to the amount of work performed. 

 For train signalling apparatus, and for ringing bells, these batteries have 

 been found to answer well for long periods of time. The inventor states 

 that the Electromotive Force is 75 per cent, greater than the Daniell 

 Battery, whilst its resistance is 90 per cent, less : and gives the following 

 instructions for charging, which should be carefully attended to. 



2 F 



