Part of a Letter from Dr. Wolfe, at Warsaw, to Henry Baker, F. R. S. Communicated by Mr. Baker

XXI. Part of a Letter from Dr. Wolfe, at Warsaw, to Henry Baker, F. R. S. Communicated by Mr. Baker. Warsaw, April 15, 1768. Read May 12, 1768. OUR winter has been very long and very severe. The frost was at a medium, from the middle of December to the middle of March, at nine degrees of Reaumur's thermometer below the freezing point. Three times it was from 19 to 20 degrees, and very seldom ascended to the freezing point. Last year the frost was at 24 degrees, but of no duration. In the year 1740 it was at 26 degrees, which, perhaps, is the lowest it has been remembered in this country. This year we have had little or no snow, which made the frost exceedingly more sensible. The barometer is here, at a medium, at $28 \frac{1}{3}$ inches Rhinland measure: great storms sink it two inches lower; and very dry weather raises it $1 \frac{1}{3}$ inch higher. The declination of the needle at this place is eleven degrees and half to the west. XXII. Extract