. Sse OO ee 
2 ar 
a 
Positive spark from } inch 
a 
aa eet 4 
Figures by the Electrie Spark. 291 
i verge al 
| center, but generally the 
; central portion is broken 
up into a confusion of 
balls. Striking dis- 
tance, } inch, 
Negative spark from + inch halls. iat 
Striking distaz similar figures were obtaine 
by — si saguam eans of the electricity developed 
by the Holz machine, the’ electophorus and that accumulated 
ma Leyden jar.* : 
harge from Points—When a single, instantaneous dis- 
the &” from a fine point, falls upon the film, fi similar to 
© foregoing, but not so regular, are obtained. If, however, 
Tn experimenting with d Leyden jar, if the electrodes D and E 
(fg. 1) are ctininscted with the Secine dae te jar, det discharge is so violent as to 
Sein the film of pitch. Surrounding the minute perforation is a circular crack. 
the brigh : : ’ a ; 
fer ei eget exposed, a minute dot is seen. pe eager mgsee Glare 
*lectrie action of the tin, and iron, is proved by the fact that the fusion takes place 
