20 



CONTRIBUTIONS TO ELECTRICITY AND MAGNETISM. 



tive action on the adjoining secondary conductor. The amount, therefore, of 

 induced current produced during any moment of time will be just in propor- 

 tion to the corresponding increase in the current of the battery during the same 

 moment. Also, the amount of induction during any moment while the cur- 

 rent of the battery is diminishing in quantity will be in proportion to the de- 

 crease during the same moment. 



60. The several conditions of this experiment may be represented by the 

 different parts of the curve, A, B, C, D, Fig. 17, in which the distances, A a, 

 Ab, Ac, represent the times during which the battery is descending to differ- 

 ent depths into the acid; and the corresponding ordinates, ag, bh, cB, repre- 

 sent the amount of current electricity in the battery conductor corresponding 

 to these times. The differences of the ordinates, namely, ag, mh, nB, express 

 the increase in the quantity of the battery current during the corresponding 

 moments of time represented by A a, ab, be: and since the inductive actions 

 (59) are just in proportion to these increases, the same differences will also re- 

 present the amount of induced action exerted on the secondary conductor 

 during the same moment of time. 



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61. When the battery is fully immersed in the acid, or v/hen the current in 

 the conductor has reached its state of maximum quantity, and during the time 

 of its remaining constant, no induction is exerted ; and this condition is ex- 

 pressed by the constant ordinates of the part of the curve B C, parallel to the 

 axis. Also, the inductive action produced by each diminution of the battery 

 current, while the apparatus is in the progress of being drawn from the acid, 

 will, in a like manner, be represented by the differences of the ordinates at the 

 other end, CD, of the curve. 



62. The sum of the several increasements of the battery current, up to its 

 full development, will be expressed by the ordinate cB, and this will, there- 

 fore, also represent the whole amount of inductive action exerted in one direc- 

 tion at the beginning of the primary current; and, for the same reason, the 



