Mr. Read's Meteorological Journal 
244 
Days. 
Wind. 
Barom. 
Ther. 
Sparks. 
Pos. 
Neg. 
Oct. 16 
w 
Inches. 
3°-34 
O 
43 
small 
pos. 
Six o’clock A.M. balls three-tenths of 
1 7 
s 
3 0>I 5 
55 
small 
DOS. 
an inch open. The pith balls have not 
been unelectrified this day. 
During a continuance of moderate wea- 
18 
sw 
2Q.QO 
62 
small 
pos. 
ther, I have frequently observed that 
the atmospherical electricity has periods 
of increase and decrease of quantity, 
which are tolerably regular ; I shall 
therefore be accurate in my account of 
this day’s variation, as it may serve for 
an example of reference to many other 
days when similar appearances took 
place. When I left the rod last night, 
the pith balls were one inch open, po- 
sitive. Six o’clock this morning, I 
found them three-tenths of an inch 
open, positive ; and soon after this I 
perceived them to open wider and wider, 
so that a little before nine o’clock, the 
pith balls were stationary at near two 
inches open. But as the sun advanced 
towards the meridian, the electric charge 
in the rod decreased ; and it was only 
possessed of various degrees of a weak 
intensity until four o’clock P.M. : the 
pith balls were then only two-tenths of 
an inch open. Half an hour after four 
o’clock, they began to increase their di- 
vergency, which gradually held on till 
a little after seven o’clock, when they 
again became stationary at full two 
inches open ; a little after eight o’clock, 
they began to decrease ; nine o’clock, 
they were one inch and a quarter open ; 
near eleven o’clock, I left them at a 
bare inch open. 
Six o’clock, pith balls two-tenths of an 
19 
w 
30-15 
39 
small 
pos. 
inch open, positive. A dark cloudy 
morning. One o’clock P.M. some rain 
fell, yet the electric charge in the rod 
was positive. Near three o’clock,, the 
fall of rain suddenly increased, so did 
the electric charge in the rod ; and at 
the same time changed to negative, 
with sparks ; and after this ended posi- 
tive. 
The rod has not been unelectrified this day : 
and the facts and appearances have been 
nearly like those of the 1 7th instant. 
