ELECTRIC C«WIMN. 
50 ^ 
a new kind of pbysicfil perpetuum mobile, with the circum- qnfnry of 
stance that it exhibits almost to the eye the electro-motion in 
the column, explained in my former pa|^er, by comparing the 
pendulum to a bucket which, when filled with electric fluid by 
its communication with the positive extremity of the column, 
transport tliat fluid to the. negative j and, by the property of the 
column, producing again its motion towards the positive 
extremity, there is thus a perpetual circulation of the electric 
fluid by the alternate strikings of the pendulum, which are 
only more or less rapid in different days, and different parts of 
each day, according to the electric state of the ambient air; 
and these changes were at first the only object which I had in 
view in continuing to observe them ; but afterward a new 
1 phenomenon attracted my attention. 
My window is turned towards the south, and the distance at occasioned bv 
(which my apparatus is from it, prevented the sun from shining 
ton the table in summer, because as it was too high ; and this 
(continued till the beginning of October ; but at last its rays fell, 
rnot only on the table, but on the column itself ; and then 1 
observed so great an increase in the frequency of the strikings, 
tthat it became a new object of observation, which, however, is 
mot often possible, at least in my roora^ because, in this season, 
fthe sky is frequently cloudy, or so hazy as to w eaken the rays of 
tihe sun ; but during many days I have been able to make tlie 
ifoHowing correspondent observations. 
* Before the sun shines on the column, w'heti, however, its 
rays begin to fall on the table, I count the number of strikings 
n one minute : they never exceed 15, and very often they arc 
jnly 12. But when the sun’s rays fall on the cmlumn itself, I 
.aave often countt3d 25 ; then when the sun retires, the number 
liminishes and returns to that of the morning. 
This phenomenon might be supposed to depend on the The Kpbt does 
Hifferences of heat produced by the sun’s rays in the column j “ 
iivhicli is a question of natural philosophy deserving notice, as it 
•lafes to the important object of the effects of die sun’s rays in 
j»e atmosphere ; of which I sliall sjienk, after having removed 
aat explanation by a direct exi>eriaicnt oa the column itself. 
related 
