PHILOSOPHICAL 
TRANSACTIONS. 
X 
* 
XXII. An account of experiments for determining the variation 
in the length of the pendulum vibrating seconds , at the princi- 
pal stations of the Trigonometrical Survey of Great Britain . 
By Capt. Henry Kater, F. R. S. 
Read June 24, 1819. 
Before I enter upon a detail of the operations which form 
the subject of this Paper, it may not perhaps be improper to 
give a brief statement of the occasion to which they owe their 
origin. 
The subject of weights and measures having for some 
time past been before the British Parliament, an Address 
was presented to His Royal Highness the Prince Regent, in 
pursuance of a resolution of the House of Commons of the 
15th of March 1816, to the following effect. 
“ Resolved, that an humble address be presented to His 
“ Royal Highness the Prince Regent, that he will be gra- 
“ ciously pleased to give directions for ascertaining the length 
“ of the pendulum vibrating seconds of time in the latitude 
“ of London, as compared with the standard measure in the 
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