192 TROWBRIDGE. — IIIGH ELECTROMOTIVE FORCE. 
field of Geisler tubes from the positive terminal to approximately two-thirds of the 
distance between the pointed terminals in the tube. 
A candle flame, therefore, was placed on the line between pointed terminals. 
These terminals were then moved toward each other until the effect upon the flame 
was symmetrical ; that is, when the flame assumed a flattened shape somewhat like an 
on its smaller end. It was then found that the distance of the negative 
no *v-«mi 
terminal from the centre of the flame was 5 cm., and the distance of the positive 
terminal 10 cm. It seems, therefore, that even at atmospheric pressure something 
analogous to the Faraday column begins to manifest itself. In a Geisler tube at 
suitable pressure, as is well known, this column is steadily driven back from the 
cathode space as the vacuum rises. 
In general experiments on the effect of an electrical field on the flame of a candle 
with a symmetrical field, I obtain with the terminals of an accumulator of 20,000 
previous observers who worked 
, i 
With pointed terminals it is very evident that the outer mantle of the fla 
repelled by the positive terminal of the battery. When the flame is close to this 
terminal, and is attracted by the negative terminal, the candle is close to the 
latter. When th 
o 
the form of a blunt point, a wing of 
outer envelope of the flame is attracted to the surface of the blunt terminal and 
und the point, sometimes touching the sharp po 
g away 
from the point. This action seems to be due to the deposition of soot on the poinl 
I have spoken of the egg shape of the flame when it is apparently acted upon 
equally by the positive and negative terminals; and perhaps this remark requires 
further elucidation. When, for instance, the negative terminal is brought close to 
edge of the luminous part of the flame, not touchino- it, and 
moved toward 
po 
the flame shortens and spreads out laterally 
When, however, the negative terminal touches the outer mantle of the 
effect of attraction to it becomes more marked. In these cases it would be difficult 
flame 
(1 - o 
iisli the negative terminal from the positive by the actions on the flame. 
When, however, the terminals are approximately twice the striking distance of the 
battery, the flame of the candle is a ready indicator of the nature of the poles of 
the battery being repelled by the positive pole and attracted by the negative. 
When the positive terminal is a small sphere, the repulsive effect seems more 
marked than the flattening effect. When the terminals are slowly brought near each 
1 Xeureneuf, Annates rle Chemie Pt A* pw; y* , r T 
1881 ; l-ouillet, Arm. da Chemie et de Phy^TxxXV ^'m *™ '' "^ °"* : ***** ** XY% P> ^ 
