[To face pa$t 244. Phyf. 67.] 



The MEAN STATE of the ATMOSPHERE in St Peterfburg, for Sixteen Years, extra&ed from a Regifter of the 

 Weather, kept by Profeflbr Euler, perpetual Secretary to the Imperial Academy of Sciences. 



:, July, Augurt, September and October, 



For the fix Winter Months, November, December, January, February, March 

 and April, which m:ike 181 days of the common year. 



For the fix Summer Months, May, Jui 

 which make 184 days of the year. 



I. 



BAROMETER. 



5 feet above the mean level of the Neva, and at 6o;o feet from it 

 j the Gulph of Finland. 



At highefl, 2887 commonly in January. 



Ac loweft, 26.99 



Difference, 

 Mean height, 

 It ftands 95 days 



ofteneft in Novcmbei 



tween thefe 



Th- 



5 days beloi 



N. B. The fcale of the barometer is divided into Paris inches and bin 

 dredth parts. 

 At higheit, 2S.47 ofteneft in May or October. 



At lowed, 2 7-5° ofteneft in September or Oflober. 



Difference, .92 The mean between thefe extremes is 27.96. 



Mean height, 28.04 Paris inches. 



Its height for 107 days is above 28 inches, and for 77 days below it. 



Greatcft cold, 196 

 Leaftc'old, 141° 



II. THERMOME 



De i. 'Isle's Thermometer in the lhade, and expofed to the north, the inftrument in 

 ■nmonly in January, equal to 24 below □ of Fahren- Greateft heat, 



IIEIT, or 24°^ of Reaumur below 0. 



November or April, equal to 57 of Fahr. above o, or Leaft heat, 



j c £ of Reaum. above o. 



t e r. 



ufe in the Imperial Academy of Sciences. 



commonly in July or Auguft, equal t 



144 ° 



above o, or to 24°^ of Rea 

 in May or October, equal to 41 1 

 3 of Reaum. above o. 



of Fa: 



Difference, $S° equal to 64 of Fahr. or 28°| of Reaum. 



Mean cold of the night, 162 equal 23 of Fahr. above o, or equal 7° of Reaum. 



below o. And of the afternoon, 154 equal 27 of Fahr. above o, or equal z° 



of Reaum. below o. 

 The cold has been above 1 70° for 47 nights, equal to 8° of Fahr. above o, or equal 



to io°§ of Reaum. below o. And above 15c , or the freezing point, for 156 



nights. 

 The mean term of the firft froft, the 9th October, new ftile. 

 The mean term of the Neva freezing, the 27th November. 



Difference, 38 equal to 46°^ of Fahr. or equal to 20°-j of Reaum. 



Mean beat of the afternoon, 127 , equal to 39 of Fahr. above o, or equal to ta" 

 of Reaum. above o. And of thenight, 136 , equalto 49 of Fahr. above o T or 

 to 2°5 of Reaum. above o. 

 The heat of the afternoon has been 130 , equal to c,6° of Fahr. above o, or io°5 

 of Reaum. above o; and above 150 for 182 days: That is to fay, thatthether- 

 r has been fo many days above the freezing point, 

 n of the lad froft, 3d of May, a 



Then 

 The 1 



1 of the opening of the Neva, 19th of April. 



III. w 





I N D. 



Perfect calm, 28 daya. Light breezes, 87 days. 





Perfect calm, 41 days. Light breezes, 75 days. 



Brill; gales, 5 o days. Strong gales, 16 days. 





Brilk gales, 53 days. Strong gales, 15 days. 



N. 14 days. E. 23 days, S. 20 days. W. 45 days 





N. 32 days. E. ig days. S. 22 days. W. 27 days. 



N.E. 19 S. E. 12 S.W.22 N.W. 26 





N.E.ij S.E. 18 S.W.24 N.W.27 



IV. SKY AND 



A 



TMOSPHERE. 



Sky clear, 39 days. Cloudy, 68 days. Overcaft, 74 days- 





Sky clear, 53 days. Cloudy, 87 days. Overcaft, 44 days. 



Fog, 26 





Fog, 17 



Rain, 2d 





Rain, 80 , 



Snow, 64 Mean term of the firft fnow, Oft. 9. N.S. 





Snow, from 6 to 7 days. Mean term of the laft fnow, 4th of May, N. S- 



Qu.Jitity of rain and melted fnow, 4^^,' or about 5 inches. 





Quantity of rain-water, ic^, or about 11 inches. 



Aurora BorcnlU, 16 or 17 days. 





- Aurora Borealis, from 8 to 9 days. 



Tempeft, feldom. 





Tempefts, from 11 to 12 



Hail, very feldom. 





Hail, from 2 to 3 — 



