fame Electrical Experiments . 49 
When I intend to obferve the electricity of the atmo- 
fphere with this inftrument, I thruft the pin 1 into the 
cork d, and holding the rod by its lower end a, project it 
out of a window in the upper part of the houfe, into 
the air, railing the end of the rod with the electrome- 
ter fo as to make an angle of about 50° or 6o° with 
the horizon. In this lituation I keep the inftrument 
for a few feconds, and then pulling the twine at h, 
I difengage the pin from the cork d, which operation 
caufes the firing to drop in the dotted fituation l k, and 
leaves the electrometer infulated, and electrified with an 
electricity contrary to that of the atmofphere. This done, 
I withdraw the inftrument, and examine the quality of 
the electricity without any obftruCtion either from wind 
or darknefs. 
With this inftrument I have made obfervations on the 
electricity of the atmofphere feveral times in a day, and 
have kept a journal of thofe experiments from the 27th 
of September laft to this day. 
The following is the molt remarkable part of the 
above-mentioned journal, in which I have noted the 
electricity of the - electrometer,' that is the contrary of 
that in the atmofphere. 
The ftroke fignifies as above. 
Vol. LXVIL 
H 
Time 
