Observations and HfiMons on Storms, &fc. 359 



The crucible was then placed in a hijjh heat for two hours, 

 and withdrawn quite entire. When cold, i found a fine im- 

 palpable powder of charcoal of a deei) velvet black which 

 weighed ri grains. The treatment in this experiment was 

 every way nniilar to the former (No. III.), yet only eight 

 grains of charcoal were here miffing. 



X.X. Obfervations and Refactions on Storms, and fomc 

 other Phenomena of the Atmofp^ere. In a Letter from 

 Profeffbr Waterhousk to Dr. Mitch ill, dated 

 Cambridge, MaJJachufetts, March 20, 1802. 



<C Tf DEAR SIR, 



Y OUR letter of the 8th inftant, requeuing information 

 of the precife time the late wide-fp reading ftorm commenced 

 at this place, came to my hands evening before laft. I haften 

 to gratify you as far as I am able. 



"Sunday, the 21ft of February, the day preceding the 

 ftorm here, was remarkably calm and pleafant. The imoke 

 afcended from the chimneys in a ftraight column. The ther- 

 mometer at noon was 47. Neither hygrometer nor barome- 

 ter indicated, at that period, any difpofition of change in 

 the atmofphere. As late as half pall ten at night, the fky 

 was clear and ftar-light. At about two hours and a half 

 after this, viz. one o'clock in the morning of the 22d, the 

 fnow-ftorm began. My information comes from an intelli- 

 gent market-man, who-fet out from his own houfe for Cam- 

 bridge at midnight. Excepting for a few hours on Wednes- 

 day, 24th, we faw not the fun for nine days. It was the 

 longed if not fevereft fnow-ftorm I ever knew. 



" I here fend you an abftra6l from the official meteorolo- 

 gical obfervations * kept in this univerfity by Mr. Webber, 

 * Some Meteorological Obfervations, 

 Ba>om. Toer. Hygr. Wind. Tbf Sky. 



Feb. 21, 9 P.M. 29 So 27 56 N. W. weak. Few clouds. 

 22, 7 AM. 29 60 25 84 N. very ftrong. Wholly cloudy. 

 2 P. M. 29 30 17 83 Do. Do. 



9 P. M. 29 24 12 83 Do. Do 



23,7 A.M. 29 6 i<- 1 80 N. W. very ftron g. Moflly cloudy. 

 •* A fevere fnow-ftorm continued through the whole of the 22d. The 

 falling fnow was very thick; the wind very ftrong, and fomewhat to the 

 E. of N. but appearing to me, by the college vane, to be nearer to the N. 

 than the N. E. It was noted N. 



f* The fcale of the barometer is French mcafure, but is here reduced to 

 the Englifh or common fcale, and correction made for the cflFetr of varia- 

 tion in temperature. The inftruments are placed without a north cham- 

 ber window." 



Z 4 profeflbr 



