[ *37 ] 
wire, both being infulated, and (landing five inches 
from each other, fee Fig. 5, I placed a large cop- 
per ball, C, eight inches in diameter (infulated 
alfo) fo as to (land exactly at half an inch diftance 
both from the knob and the point. The jar being 
fully charged, I delivered it upon the copper-ball 
by my difcharging rod, whence it leaped to the 
knob A, which was three quarters of an inch 
in diameter, and the jar was difeharged by a: 
loud and full explofion, and the chain was very 
luminous. 
Thefe experiments were made in the pretence 
of Mr. bell, a very ingenious electrician, whofe 
province it was to be particularly attentive to the- 
phenomena, and he could perceive no light upotv 
the chain, which connected the pointed wire B,- 
with the coating of the jar. 
EXPERIMENT VI. 
I infulated my three largefl jars, containing to- 
gether about fixteen fquare feet of coated furface. 
From the bottom of thefe jars projected a wire, 
terminated by a ball, three quarters of an inch in 
diameter ; and, at the diftance of one inch and an 
half from it, I placed the infulated ball C. Fig. 6, 
on which I brought down the charge of the three 
jars, by my difcharging rod ; which leaped from 
thence to the ball in contact with the jars, and 
difeharged them, by a loud and full explofion ; but 
the fame thing did not happen, if I removed the 
infulated ball only one eighth of an inch further 
from the other. I then removed the wire, which 
Vol. LXIV. T was 
