New Evidence, etc. 385 
of which are of red granite. The room containing the 
apparatus is in the second story of this building, and 
below this tower. 
Twelve copper wires about ten feet in length were sol- 
dered to the lower part of the lightning rod, and spread 
over the ground, their ends being injected a few inches 
into the soil. The wire leading from the masses within 
the building to the rod was also soldered to it. Connected 
with this wire within the room containing the gravitating 
masses were metal rods surrounding the apparatus on 
which were hung sheets of metal to which were attached 
about one thousand pins. Small holes were punched 
through the metal, the pins were inserted, and the heads 
were soldered to the metal. This was intended as a means 
to put all of the air in the room in an electrical condition 
as near uniform as possible. ; 
With such an apparatus a determination of the gravita- 
tion constant would be utterly impossible. The position 
of the suspended masses changes from day to day and 
from night to day by greater amounts than was at any 
time possible when the plate-glass machine was used for 
electrification of the masses. Their position depends 
upon the weather and upon the moisture in the surface 
of the earth. The changes were often greater than was 
ever caused by the removal or replacing of the large 
masses. Results obtained on December 12th last are 
alone sufficient to establish the fact that enormous local 
changes in the earth’s potential are constantly occurring, 
and that these changes produce variations in gravita- 
tional attraction between the large masses and the sus- 
pended masses. 
On December 5th and 6th over an inch of rain and sleet 
fell, and on December 8th and 9th there was a light fall of 
sleet. The minimum temperature gradually fell from 
28° on the 5th to 1° on the 10th. The ground was cov- 
ered with a thin layer of ice and snow on the 12th. On 
that day the morning temperature was 20° but rose to 56°. 
The ground around the lightning rod between the build- 
