428 
MESSRS. T. E. THORPE AND J. W. RODGER OH THE RELATIONS 
SLifficient length of mercury had been introduced, by quickly laying the glischrometer 
flat on the table, the excess of mercury contained in the globule was detached into the 
left limb. The jDOsition of the thread which nearly filled the bore was then made as 
nearly as possible equidistant from the ends of the capillary. 
The length I of the thread was then ascertained by the calibrating instrument, eight 
measurements, as a rule, being made when the thread was parallel to the line of 
motion of the reading microscojDe and when either side of the glischrometer was 
uppermost. 
When the length had been accurately measured, by tilting the glischrometer the 
thread was completely transferred, in the form of a globule, into the right limb. By 
judiciously tapping and tilting the glischrometer, the globule was next very gradually 
moved to the free end of the limb, its course being followed with a lens in order to 
see that no separation into smaller globules took place. The globule was finally 
received in a small weighed glass tube which fitted into a slightly wider tube. The 
tubes together weighed less than 1 gram. 
The weight W of the globule, which was but some ’013 grm., was then ascertained. 
The weighings were performed on an assay balance by the method of vibrations. The 
sensibility of the balance was about 7 (1 scale division corresponded to less than 
'00014 grm.) The zero point and the sensibility were determined before and after 
each weighing. Keduction of the observed weight to a vacuum was unnecessary 
since mercury wms weighed against platinum. By the use of the ordinary formula, 
R. = ^/{Wjirpl), on introducing the necessary corrections for the expansion of the 
brass scale of the calibrating instrument, and for the expansion of glass and change 
in p, the density of mercury, the mean of two concordant determinations carried out 
as above gave for R the mean radius of the capillary at 0°, 
'0082018 centim. 
If A and B are the semi-axes of the elliptical section of the tube, on taking the value 
of the ratio A/B, as already obtained by the optical method, and using the above 
value of R as the true mean radius of the tube, the values of A and B are found to be 
A = '0084374 centim. B= '0079728 centim. 
At 0*^ the coDstants of the glischrometer thus obtained were as under 
Volume, right limb = Vr. = 2'6731 cub. centims. 
Volume, left limb = Vl. = 2'5512 ,, ,, 
Length of capillary =l =4'9326 centims. 
Section of J Major axis = A = '0084374 centim. 
Capillary [Minor axis = B = "0079728 ,, 
Detennination of Temperature .—Two sets of thermometers, each consisting of two 
