[ 46 ° ] 
ficulty, I procured from Hawkhill and from yonrfelf the 
regiiler of the thermometer for three years, at the fame 
periods of time; copies of which I here inclofe you. 
And by thefe it appears, that the mean heat of London 
of thefe three years exceeded that of Edinburgh by 
4.5. And the mean heat of the three hotted: months in 
London exceeded the mean of the fame three at Edin- 
o 
burgh by 5 . 8 . And the mean heat of thefe three fummer 
months, at two o’clock in the afternoon, in London ex- 
- ceeded the mean heat of the fame months, at the fame 
o 
hour, in Edinburgh by 7.3 ; which fufficiently accounts 
why fome fruit may come to maturity in one country and 
not in the other : and alfo why corn and grafs, which ve- 
getate with a more temperate heat, but require a longer 
continuance of it, may arrive at maturity in both countries. 
The reafon why the mean heat of London exceeds that of 
Edinburgh may arife principally from the difference of 
latitude. But the reafon why the excefs is greater in pro- 
portion in the three hottefi months of the year, at the 
hotted: time of the day, than in the winter months, arifes 
from Edinburgh’s being fituated nearer, to the fea than 
London. We might fpeak with more precifion on this 
fubjeff, if we had a regifler of the thermometer at Mof- 
cow, which is nearly of the fame latitude as Edinburgh; 
though it is well known, that the heat of fummer is 
much more intenfe, and the cold of winter much more 
fevere, at Mofcow than at Edinburgh. The mean heat 
of fprings near Edinburgh feems to be 47°; and at Lon- 
’ don 
