Dr. Holmes’ meteorological observations. Ill 
The coldest day, according to my observation, was 2 Jan- 
uary, 1791, when the mercury was at : +17" 
The coldest, according to Dr. Holyoke, was 17 January, te 11 
1786, and 23 January, 1792, when the mercury was at 
Difference between extreme cold at Midway and Salem "98° 
On the 23d of January, 1792, when the mercury fell to 11° below 
the cypher at Salem, it fell to 20° at Montreal.* The difference 
therefore between the extreme cold at Montreal and Midway is 37°. 
Limited as the Mipway observations are, they probably reach 
nearly to the eatremes of heat and cold in the climate, in which they 
were made. In the eighteen years’ observations at Charleston, South 
Carolina, it is observable, that the mercury at no time rose above 101°, 
or fell below 17°; the greatest ascent being two degrees only above 
my maximum of heat; and the greatest descent, in exact coincidence 
with my maximum of cold. Drayton says however, that the mercury 
has fallen as low as 13° in the lower country of South Carolina. 
In the coolest summers of Carolina, it appears, that the mercury 
reached 88°; and in eight years. (from 1791 to 1798) it never rose 
above 93°, or fell below 17°. Hewatt} says, he has seen the - mercury 
in Fahrenheit’s thermometer rise in the shade to 96° in the hottest, 
and fall to 16° in the coolest season of the year. “ In 1788,” gov- 
ernor Drayton says, “ it rose to 96°, which is the greatest heat we 
know of since the year 1752. The difference therefore between our 
coolest and warmest summers at this time may be supposed to range 
between 89° and 96°; and the difference of our mildest and severest 
winters between 17° and 34°.” 
* Memoirs of Academy, ii. part 1, p. 118. 
+ Author of the History of South Carolina and ewe ; Whose residence 
' wasn Charleston., 
