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XXII. An Account of Experiments made with an Invariable 
Pendulum at JV'ew South Wales , by Major-General Sir Tho- 
mas Brisbane, K. C. B. F, R. S. Communicated by Captain 
Henry Kater, F. R. S. in a Letter to Sir Humphry Davy, 
Bart. Pres. R. S. 
Read June 19, 1825. 
Sir, 
In compliance with the request of Major General Sir 
Thomas Brisbane, I have the honour to lay before the 
Royal Society the results which I have deduced from his 
experiments, made with an invariable pendulum at London 
and at Paramatta. 
The pendulum employed belongs to the Board of Lon- 
gitude, and is of the same construction as that which I 
used at certain stations of the Trigonometrical Survey of 
Great Britain. Before Sir Thomas Brisbane's departure, I 
observed the following series of coincidences at Mr. Browne's 
house in Portland Place, London, in order to determine the 
number of vibrations made by this pendulum in twenty-four 
hours. 
