|Alternative reference number
|Copy letter from Robert William Frederick Harrison, to the Government Astronomer, the Observatory, Madras [Chennai]
|8 July 1897
|Harrison is now able to answer the enquiry contained in his correspondent's letter of the 26th May.
In the Kew Observatory records there are particulars of an extensive comparison of the Royal Society's barometer with flint and crown glass tubes with the large Kew Standards through the intermediary of Newman 34, in 1181. This comparison would not appear of any use for the purpose of his cortespondent's enquiry as in the Kew Report for 1877 it is stated that the old Royal Society's standard, which has been in a defective condition since its removal from the Society's rooms in Somerset House in 1857, has been thoroughly repaired and both its tubes refilled. After such treatment is could not be assumed that no change in index error had occurred.
The large barometer at Kew set up by Welsh was not erected until 1856 or 1855, and it is doubtful whether any comparison of the Royal Society's barometer was made with any standard at Kew before 1881.
The Royal Society's barometer is presently being used to determine boiling point pressures in connection with investigations in platinum thermometry, for which it is very suitable.
At present its correction is .005 of an inch. There is a paper apparently by Mr F Baily, on the early days of the Royal Society barometer in the 'Philosophical Transactions [of the Royal Society]' for 1837.
|see also NLB/15/126
Fellows associated with this archive
|Baily; Francis (1774 - 1844); astronomer
|1774 - 1844