FORCE OF THE WESTON NORMAL CELL IN SEMI-ABSOLUTE VOLTS. 
173 
Table IX. 
Diameter of Cylinder I. in Centimetres. 
2-0180 
2-0180 
2-0182 
2-0183 
81 
80 
82 
81 
80 
79 
80 
81 
80 
81 
81 
81 
85 
83 
81 
84 
85 
82 
82 
85 
82 
83 
82 
83 
82 
81 
80 
83 
84 
81 
80 
85 
81 
81 
80 
82 
Means. . 2 - 0182 0 
2 ■ 0181 j 
2-0181,, 
2-0183 0 
Mean diameter of Cylinder I. = 2 - 0181 s cm. 
Diameter of Cylinder II. in Centimetres. 
2-0180 
2-0180 
2-0181 
2-0180 
80 
80 
80 
79 
80 
80 
80 
80 
79 
79 
77 
75 
75 
81 
83 
83 
79 
80 
80 
80 
79 
81 
81 
81 
80 
81 
82 
81 
82 
84 
84 
82 
80 
81 
81 
80 
Means.. 2 • 0179 4 
2-01807 
2-0180a 
2-0180, 
Mean diameter of Cylinder II. = 2 - 0180 3 cm. 
(c) The Linear Measurements. 
Before proceeding with the records of results involving linear and time deter¬ 
minations it is perhaps necessary to describe briefly the methods used. Linear 
measurements were made on a steel Queen Company comparator fitted with high 
power microscopes. Experiment showed that with care it was possible to transfer 
the tube from the dynamometer to the comparator without jarring the cylinders apart 
to any perceptible amount. A Geneva brass metre with inlaid silver scale was used 
as the standard for comparison. This involved careful attention to temperature, but 
a calibration of this scale showed such fine marking and accurate sub-division that it 
was used in preference to two Konstat metres which has been certified at the National 
Physical Laboratory, Teddington, for the full length, but which were not very 
accurately sub-divided. A comparison of the brass standard with the Konstat 
