LOltD 11AYLEIGH. 



two succeeded; while for the failure of the third there was some expia- 

 nation. The bullet without condenser was now distincly superior to the 

 best ordinary break with condenser. 



The next step was the substitution of a n/fe-bullet, fired from a ser- 

 vice rifle. Here again the bullets were reduced to about one-half, and 

 after cutting the wire were received in a long box packed with wet 

 sawdust. At 60 mm., while the mercury-under-oil break with condenser 

 gave only feeble brush -discharges, good sparks were nearly uniformly 

 obtained from the bullet working without a condenser. At 70 mm. the 

 bullet without condenser was about upon a level with the mercury- 

 under-oil break with condenser at 60 mm. As regards the strength of 

 the primary current, if there was any différence, the advantage was 

 upon the side of the ordinary break with condenser, inasmuch as in the 

 case of the bullet the leads were longer and included about 8 cm. of 

 finer copper wire where the bullet passed. 



In the next set of experiments upon the same Apps' coil excited by 

 three Groves, the bullet was used each time, and the comparison was 

 between the etfect with and without the usual coil condenser. At 55 mm. 

 the bullet without condenser gave each time a fair or a good spark, 

 while with the condenser there was nothing more than a feeble brush 

 scarcely visible in a good light. 



The single pane of coated glass was next substituted for the usual 

 condenser of the coil, with the idea that possibly tins might be useful 

 although the larger capacity was deleterious. But no distinct différence 

 was detected when the ballet was fired with tins or without any con- 

 denser. 



In the last set of experiments now recorded the primary current was 

 raised, six Grove cells being employed partly in parallel, and the wire 

 was eut each time by a rifle-bullet. At U0 m m no spark could be got 

 when the coil condenser was in connexion; when it w r as disconnected, 

 a spark, good or fair, was observed nearly every shot. 



Altogether thèse experiments strongly support the view that the only 

 use of a condenser, in conjunction with an ordinary break, is to quic- 

 ken it by impeding the development of an arc, so that when a sufficient 

 rapidity of break can be obtained by other means, the condenser is 

 deleterious, operating in fact in the reverse direction, and prolonging 

 the period of decay of the primary current. It is hoped that the esta- 

 blishment of tins fact will inspire confidence in the theory, and perhaps 



