[ * 5 * ] 
XXI T. ExtraSl of a Letter from Mr. Peter 
Wargentin, Secretary of the Royal Acade- 
my of Sciences at Stockholm, and F. R. S. 
dated February 23, 1768, to the Reverend 
Nevil Mafkelyne, R. D. F. R. S. AJlro- 
nomer Royal. 
Read May 12, S it is related in the public newf- 
/ \ papers, that the weather* has been 
uncommonly cold in Germany, England, and France, 
towards the end of lafl year, and the beginning of 
the prefent year, I have here fent you the degrees 
of altitude by Reaumur’s thermometer, as I have 
oblerved them fmce the beginning of November 
1767. The altitudes here fet down are the arithme- 
tical means of three taken every day, viz. in the 
morning before fun-rife, a little after noon, and at 
ten o’clock at night. Hence it appears that the cold 
has been moderate here with refpedt to this climate, 
and nothing more than common, though it was with- 
out intermifiion, from the beginning of December. 
The greateft cold in thefe months happened on the le- 
cond day of January in the morning; the quick-filver 
then flood at 17,2 below the point of freezing. 
* The lead height of Fahrenheit’s thermometer, fet down in 
the courfe of the aftronomical obfervations made at the Royal Ob- 
fervatory, was 15 0 on Jan. 6, at the tranfit of Venus over the 
meridian at 8 h. 42. m. A. M. At which time nearly the 
fame was obferved by my Lord Charles Cavendith in Great Mal- 
bro’ Street, at 17 0 . But by a thermometer defcribed in Vol. L. 
of thefe Tranfactions, placed on the top of the fame houfe, in a 
very bleak iituation, Dec. 31. it appeared to have been at 12 J 9 
in the preceding night ; Jan 3. i6°; Jar.. 6. 16°, and Jan. 7. 
