244 
MESSRS. R. T. GLAZEBROOK AND J. M. DODDS ON THE 
—was not absolutely constant throughout an experiment. Now the observations of 
deflection refer to a moment of time about half way between the two throws, so that 
the mean of the two values of Pi+p% will give us the value of that quantity corre¬ 
sponding to the value of qi+q% obtained for the deflections. 
For the first series of observations the difference in the values of p x before and after 
the deflection reading was sometimes, but not often, as great as 1 millim. in a throw 
of about 215 millims. 
A copy of the observations requisite for one experiment will perhaps render the 
above details more complete. 
Observation No. II., June 8th, 1881, 11*45 a.m. Observers, ft. T. G., J. M. D 
Time of swing 23"'277. 
Bridge reading value of x [IT, W direct 1 500 
fill, W interchanged J 410 
x 
It 13°*7 
Temperature. 
S 13°-7 Galv. 14°-5 
Scale observations. 
Zeros 
Throws 
235‘5 
227-5 
235 
227-8 
235 
Left. 
Right. 
70 
455 
454-5 
7-8 
225 
238 
225-2 
238 
225-2 
Zeros 
