Intelligence and Miscellaneous Articles. 399 
were soldered two German-silver wires. These two thermo-electric 
junctions were about 0*4 cm. apart, and -were separated from each 
other by densely packed asbestos. The arm was placed in a glass 
tube arranged as before. The bar was heated about 19 cm. from 
the thermo-electric junctions. By this arrangement the heating of 
the magnetic coils had an equal effect upon the two junctions ; 
while any change, due to altered conductivity, of the flow of heat 
along the bar would affect the relative temperatures of the junctions. 
When the German-silver wires were connected as before with the 
galvanometer, and the unheated bar was placed either parallel or 
perpendicular to the axis of the magnet, there was, after forty-five 
minutes' observation, absolutely no deflection in the galvanometer. 
This showed that the arrangement obviated all difficulties arising 
from heating the coil ; and moreover that the magnetic field did 
not perceptibly alter the thermo-electric relation of iron and 
German-silver. When the bar was placed perpendicular to the 
axis of the magnet, thin plates of soft iron, running the length of 
the glass tube, were placed upon the magnetic poles, thus lengthen- 
ing the field through which the bar passed. The bar was next heated 
as before. After several hours the galvanometer generally showed 
a permanent deflection of 35-40 cm., in a direction indicating that 
the junction at the end of the bar was the cooler. Several obser- 
vations were made, both when the bar was parallel and perpen- 
dicular to the axis of the magnet. The current was passed for 
about one hour ; and in every case there was absolutely no change 
of the deflection beyond the immediate change due to the direct 
action of the magnet. 
The result of these experiments seems conclusively to show 
that longitudinal and transverse magnetism, at least of the strength 
used, have no influence upon thermal conductivity of soft iron. It 
was, however, decided to try a thinner piece of iron than the 
preceding. A strip of ordinary tinned iron was therefore cut 
about 1-3 cm. wide, and was bent over and arranged exactly as 
before. The whole tube was packed with asbestos and cotton to 
avoid any motion of the strip when the magnet was made. The 
distance of the flame from the two thermo-electric junctions was 
10 cm. A heating of ninety minutes was found to be sufficient in 
this case for the strip to reach a permanent condition of tempera- 
ture. The deflection showing the difference of temperature between 
the junctions was about 13 cm. When the magnet was made, there 
was no change of the deflection after thirty-five minutes' observation. 
The strength of the magnetic field when the bar was placed 
perpendicular to the lines of force was measured after the preceding 
experiments were made, and was found to be 10,420 times the 
horizontal intensity of the earth's magnetism at Cambridge. In 
the C.G.S. system this would be about 1760. 
Aside from the experiments of Maggi, those of Thomson upon 
electrical conductivity are the only experiments that seem to be 
directly opposed to the conclusion that must be drawn from our 
observations. Magnetism undoubtedly changes several physical 
