of the Electrical Terms Intensity and Tension. 513 



represented by the triangles A e h, Afi, &c. : then, since the 

 attractive forces between the exploding points of the balls of the 

 discharger, with a given accumulation, are in the inverse duplicate 

 ratio of the distances A e, Af, Kg, &c, these attractive forces will 

 be inversely proportional to the same triangular spaces A e h, Afi, 

 Agk, &c. If, therefore, when force in the direction of the cir- 

 cuit is A e h, discharge takes place, quantity being C e, distance 

 Ae, and attractive force between discharging balls — 1, then 

 supposing A e to become Af = twice A e } the force between the 

 balls at distance Af would be only one-fourth as great ; that is 

 to say, it would be inversely as triangle A e h to triangle Afi. 

 Hence with the same quantity accumulated = C e discharge 

 could not occur at distance Af. Let now the first quantity 

 accumulated = Ce become twice as great ; that is to say, let 

 it be represented by rectangular space Cf= 2Ce: in this case 

 the force in the direction of the external circuit would be 

 represented by triangle Afi=4< times A eh; and since attrac- 

 tive force between the exploding points of the balls of the dis- 

 charger is as squares of the quantity accumulated, therefore attrac- 

 tive force through the external circuit with the double accumu- 

 lation Of becomes also four times as great; and is the same at 

 distance A/with a double accumulation as at distance Ae with a 

 single accumulation; in this case explosive discharge again ensues. 

 In a similar way it may be shown that when distance Ae 

 is extended to Ag, attractive force between the balls with the 

 single accumulation C e is reduced to one-ninth, in which case 

 no explosive discharge could occur at distance Ag. Let the 

 quantity accumulated, however, become three times as great, 

 that is to say, let rectanglar space C e become Cg ; in this case 

 the force through the external circuit is represented by the tri- 

 angular space Ag k = 9 times triangular space A e h; but since 

 these spaces are inversely proportional to the attractive forces at 

 distances Ae, Ag, attractive force at distance Ag is the same 

 with a treble accumulation, as at distance A e with a single accu- 

 mulation ; explosive discharge will therefore again occur, and so 

 on. Hence the interval at which discharge occurs, as measured 

 by a Lane's discharger L, fig. 7, will be directly as the quantity 

 accumulated ; whilst the electrometer indication or force through 

 the external circuit will be as the square of the quantity, being 

 as the triangular spaces A eh, Afi, Ag k, &c. M. De la Rive, 

 in his comprehensive treatise on Electricity, considers this result 

 as somewhat remarkable*. It is evident, however, from the 



* Ce qu'il y a d'assez remarquable, c'est que la distance a laquelle une 

 decharge entre deux balles chargees d'electricites contraires peut avoir lieu, 

 est simplement proportionnelle aux quantites d'electricite, tandis que les 

 forces attractives sont proportionnelles aux carres de ces forces." — Traite 

 d' Electricity tome i. p. 66. 



