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VI. An account of the heat of July, 1825 ; together with some 
remarks upon sensible cold. By W. Heberden, M. D. 
F. R. S . 
Read January 12, 1826. 
As I think it may not improbably be deemed an object of 
some curiosity to the Royal Society to collect from different 
parts, an account of the very unusual heat of last July, I 
presume to offer the enclosed report of observations which 
I made at that time, at Datchet, in Buckinghamshire, with 
every precaution that suggested itself to me, to ascertain the 
real temperature of the atmosphere, uninfluenced by adven- 
titious circumstances. The observations were made with a 
small sensible thermometer, which had been carefully 
graduated. 
On Friday July 15, the wind blowing from the south-west, 
the thermometer was suspended in the shade of a large 
laburnum on my lawn, at a height of about five feet and a 
half from the ground. This tree was chosen, as admitting 
the air in some degree to pass through it, at a time when the 
wind and the sun were both in the same quarter. On the 
subsequent days, the wind being in the east and north-east, 
the thermometer was hung, at about the same height, from 
an external branch of a very thick Portugal laurel, standing 
likewise upon the lawn, at a distance from any building ; 
where it was exposed to the full influence of the wind, and 
at the same time effectually sheltered either from the actual 
