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XXIX. Sequel to a paper on the Reduction of the Thermometrical Observations made 
at the Apartments of the Royal Society, By James Glaisher, Esq., F.R.S., of 
the Royal Observatory, Greenwich. 
Received December 14, 1849, — Read February 28, 1850. 
In a paper which the Royal Society did me the honour to publish in the last volume 
of its Transactions, I gave the results found from all the thermometrical observations 
which have been taken at the Apartments of this Society ; and I stated that I had 
made some progress in the connection of this series of results with those deduced 
from the observations at the Royal Observatory, Greenwich. Since that time I have 
reduced the two series of observations to one and the same series, and I have now 
the honour to lay the results from their combination before the Society. 
In my former paper I stated that no observations had been taken between the 
years 1781 and 1/86. Had the particulars of these years been about their average 
values, their omission would not have materially affected the final results, but on 
examination I found that those years were distinguished by very severe weather, and 
that their omission would have a sensible effect ; I have therefore supplied these par- 
ticulars, as detailed below. 
I also stated that it was doubtful whether the temperatures, as determined for So- 
merset House, were influenced by local causes. I have endeavoured to collect in- 
formation upon this subject, and of which I shall speak presently. 
I shall adopt the same plan in the arrangement of the final results, which I pursued 
in my former paper, and present them for monthly, quarterly and yearly periods. 
The numbering of the Tables is continued from the former paper. It may tend to 
clearness if I speak of each preliminary investigation separately. 
Determination of the Mean Temperature of the Air at Lyndon in Rutlandshire, the 
longitude of which place is 0° 3' East of Greenwich and the latitude is 52° 32' 
North, for every month in the years from 17/1 to 1799. 
The results of meteorological observations taken by Thomas Barker, Esq., at Lyn- 
don in Rutlandshire, and which seems to have been taken with care, were published 
in the volumes of the Philosophical Transactions for the years 1772 to 1799. From 
these papers I have determined the mean monthly temperatures of the air, and which 
are shown in the following Table ; — 
4 D 
MDCCCL. 
