578 
MESSRS. R. T. GLAZEBROOK AND S. SKINNER ON THE 
The values of E thus found require correcting (1) to reduce them to a common 
temperature of J 5° C. (2) for the difference between the bottle cell and the standard 
Itayleigh 1. 
Experiment 1 , July 31, 1891. 
The observed values of Y and W are shown on Plate 16. In these one vertical 
division represents 5 ohms, and one horizontal division 5 minutes. The curves 
from which the numbers were calculated were drawn to a larger scale. It will be 
seen that the value of i, as indicated by the values of Y, rose gradually for about 
25 minutes, then remained fairly steady for about 15 minutes, and afterwards began 
to fall. The mean value for Y, calculated as already described, is 3875 + 29"5, or 
3904-5. 
Three observations were taken for W; the mean value is 5722*5. Bowls I. and II. 
were used. 
Experiment 2, August 3, 1891. 
The observations are given in Plate 16. The current remained fairly steady for 
about 25 minutes, then suddenly increased considerably, the resistance changing 
in five minutes from 4585 to 4600, dropping in the next 15 minutes to 4595. The 
mean value of Y is 4591 ohms, while that of W is 5756’5. Bowls I. and II. were 
used. 
After these two experiments precautions were taken to work only when no other 
electrical work was going on in the laboratory. The current was supplied from 
storage cells in the battery room of the laboratory, and the wires conveying the 
current into the room in which the experiment was conducted were not satisfactorily 
insulated from other wires conveying a current from other cells into a different room. 
Fluctuatious in the current were caused when these other cells were working. 
Experiment 3, August 5. 
The curves are shown in Plate 16. It will be seen that the variations are much 
less ; in fact, the curves for Y and W are very approximately parallel straight 
lines, showing that the changes are almost entirely due to the alterations in the 
Leclanches. The mean values are— 
Y = 369P2, 
W = 5751-5. 
Bowds I. and II. used. 
In each of these three experiments some of the deposit in Bowl No. II. was lost in 
the washing, and the results from this bowl have not been used. 
After this the mercury rheostat was used. This consists of two parallel grooves in 
a piece of dry mahogany which were filled with mercury. A movable copper bridge 
put the two columns into electrical connection. The current entered at one end of 
