342 ELECTRICITY. 



is fastened round, or soldered to the wire E, 

 knobbed at each end; this connects the inside 

 coatings of three jars; and by four wires, such as 

 F F, the inside coatings of all the twelve jars may 

 be connected together. Each of the wires F has 

 a ring at one end, through which one of the wires 

 E passes; and the other end has a brass knob. If 

 the whole force of the battery be not required, 

 one, two, or three rows of jars may be used at 

 pleasure ; for as each of the wires F F is moveable 

 round the wire E which passes through its ring 

 and rests upon the next wire E, it may be easily 

 removed from that, and turned upon the contrary 

 wire E; and thus the communication between one 

 row of jars and another may be discontinued at 

 pleasure. 



The square box that contains these jars is of 

 wood lined at the bottom with tin-foil, and having 

 two handles on two opposite sides, by which it may 

 be easily removed. In one side of the box is a 

 hole through which an iron hook passes, that 

 communicates with the metallic lining of the box, 

 and consequently with the outside coating of all 

 the jars. To this hook is fastened a wire, the 

 other end of which is connected with the dis- 

 charging rod. 



The force of accumulated electricity, great as it 

 appears by the experiments performed with a single- 

 coated jar, is very small when compared with that 

 which is produced by a number of jars connected 

 together; and if the effects of a single jar are sur- 

 prizing, the prodigious force of a large battery is 

 certainly astonishing. Experiments of this kind 

 should be conducted with great caution ; and the 

 operator ought to be attentive not only to the 

 business in hand, but also to the persons who may 



