148 THE ROYAL SOCIETY OF CANADA 
It was found in using this method that the absolute pressure 
changed if the supporting thread did not hang plumb. 
ADJUSTMENT OF APPARATUS. 
To prevent such a change the contact was placed in a wooden 
frame which fitted tightly into a circular glass vessel. One corner 
of the frame had a piece of steel in it always placed at the 
edge of a strip of paper pasted to the outside of the glass vessel 
which was moved round until the thread, when hanging vertically was 
directly over the hook of the movable jaw. Then the position of the 
edge of the paper and the base of the vessel was marked on a large 
sheet of paper fastened to the floor of the balance. Thus, the contact 
wires, glass vessel and balance always occupied the same relative 
positions. The jaw could be moved sideways. To make sure that 
the thread always hung vertically a small lead pointer was attached 
to the lower end of the brass loop. Beneath this pointer was placed 
in the wooden base a small round brass pin. After the contact 
wires were connected, they were placed in the marked position in the 
vessel; the vessel and the movable jaw were adjusted until the pointer 
was directly over the small brass pin. This being in the same position 
for all observations, the absolute pressures could be compared. 





TABLE I, 
1 2 3 4 5 6 7 
Dried | Trans- | Dried 
Wires. Air. Kero- Gaso- [Machine | Machine} Former | Trans- 
sene. line. oil. oil. oil. former 
oil. 
mg. mg. mg. mg. mg. mg. mg. 
Platinum. 50 25 82 62 48 110 95 
Silverternee .. 44 34 86 56 49 70 62 
Copper... ee 60 50 65 39 ms 65 52 
Nickel 7. 140 50 44 84 62 74 71 
Manganin..... : 48 30-40 60 64 59 58 LA 
Constantan .... 160 100 145 62 50 97 97 
Kerry caen 200 160-170 137 138 95 166 161 
CONCLUSION. 
By comparing columns 1 and 2, Table 1, it is seen that the 
absolute pressure in kerosene is less than in air in every case. These 
results are taken from the paper by Mr. Reilley. It is also to be 
noted that these pressures do not include what might be termed the 
