[ 210 ] 
when removed but a few Yards from each other, 
have differed 2 or 3 Deg. for which no apparent Caufe 
could be afligned. So that upon the whole, it may 
reafonably enough be concluded, that the Difference 
between the Temperature of the Air in the two 
Places, is imperceptible to Senfe. I am, 
"■Dear Sir , 
Tooting, Nov. 1 3. Your, and the Royal Society's 
1 749. Mojl obedient humble Servant 
H. Miles. 
P. S. 
Upon my having obferved that the Days, in 
which my Thermometer and Mr. Cantons flood at 
the Extremes, in fome Months did not coincide, I 
was dcfirous of knowing, how much the Thermo- 
meters differed, when the Extremes did nor happen 
on the fame Day : But, upon a Comparifon, the 
Difference was never considerable, except on the 
4th Aug. at 2. p. m. when my Thermometer was 
about 6 Degrees higher than Mr. Canton's. This 
being fomewhat remarkable, he, upon hearing ir, 
had Recourfe to his Rcgifler, and found, that at 
the Time of Observation a heavy Shower of Rain 
fell j whereas we had none here : But about Six in 
the Evening came on a Thunder Shower attended 
with Rain ; fo that it fhould feem the falling Rain 
had fo great an Effeft upon the Air as to render 
it cooler, by the Degrees mentioned : And perhaps 
the Difference between the two Inflruments, at 
other Times, may have been owing to the fame, 
or a fimilar Caufe, rather than to a Jlated different 
Temperature of the Air, in the two Places. 
EX- 
