71 
together with some remarks upon sensible cold. 
south and south-west. On the hottest of these days Mr. Ca- 
vendish’s thermometer at Clapham rose to 96°. 
It is true that other accounts^ have been recorded, some in 
the Transactions of this Society, of hot days, or hot seasons, 
which may have equalled, or possibly surpassed this : but 
till within the last sixty years, the use of the thermometer 
had hardly been understood sufficiently to enable one to rely 
upon the vague statements of earlier times. 
To persons who may wish to compare this with the heat 
of tropical countries, it will not be thought superfluous to 
add, that the late Dr. Hunter, whose accuracy is well-known 
to many members of the Royal Society, has stated in his 
valuable account of diseases in the West Indies, that the 
range of the thermometer at the hottest part of the day, and 
in the hottest season of the year, at Kingston, in Jamaica, is 
from 85 0 to 90°. In the coldest season it is about 5 0 lower. 
It is not the least singular circumstance attending the heat 
of last July, that it should have subsided without rain, without 
lightning, without any change of wind, or any obvious 
cause ; the succeeding days continuing dry and fair, as those 
before. 
I am tempted to add to the above some other observations, 
which, if they are not immediately connected, are not entirely 
unconnected with this subject; for it cannot have escaped 
the attention of any person moderately conversant with 
natural philosophy, that the index of a thermometer is a very 
imperfect measure of what I may call the sensible cold , that 
is, of the degree of cold perceptible to the human body in its 
ordinary exposure to the atmosphere. For while the ther- 
mometer truly marks the temperature of the medium in 
