THE EUROPEAX STORM OF DECEMBER 21-28, 1836. 13 



drawn the line of a half inch depression helow the mean, and on three of them the 

 line of three-quarters of an inch below the mean. 



On the 21st of December the barometer was above its mean height throughout 

 the whole of Europe, except its northeastern portion, and here the greatest observed 

 depression was .41 incli. On the 22d the depression of the barometer near the 

 centre of Eussia had increased to a half inch, and the area of low barometer had 

 extended somewhat further towards the south. On the 23d the area of low baro- 

 meter had extended so as to cover nearly the whole of Europe, comprehending the 

 whole of France, and more than half of Italy; while the area of one-half inch 

 depression below the mean formed an oval figure, whose longer diameter was 1,750 

 miles, and its shorter diameter over 500 miles. On the 24th the area of low bare- 

 meter covered all of Europe, except its extreme northern portion, and there arc two 

 areas of one-half inch depression ; one having its centre near Switzerland, and the 

 other in Central Russia. The former area was an oval 870 miles long and 560 

 broad, while the latter was 1330 miles long and 520 broad. On the 25th the Swiss 

 area of a half inch barometric depression had somewhat extended its limits, being 

 now 980 miles long and 830 broad ; while the Russian area had travelled towards tlie 

 northeast, and had nearly reached the eastern limit of Europe. On the 26th the 

 Swiss oval of one-half inch depression had increased still further in its dimensions, 

 being now 1150 miles long and 930 broad; while the Russian oval of one-half inch 

 depression had passed beyond the limits of Europe. On the 27th the Swiss oval 

 had greatly contracted in its dimensions, being now only 890 miles long and 400 

 miles broad. On the 28th the area of one-half inch depression below the mean had 

 almost entirely disappeared, and the area of one-quarter of an inch depression had 

 contracted very much in its dimensions. 



The Swiss area of low barometer on the 24th probably had a different origin 

 from that of the low barometer wliich prevailed throughout Eastern Europe on the 

 23d. The latter travelled towards the northeast from December 23d to December 25th, 

 at the rate of about 40 miles per hour. The former probably originated in "Western 

 Europe, and its centre remained nearly stationary for four entire days, viz , from 

 noon of December 24th to noon of December 28th, and this centre was at no time 

 more than 140 miles from Mount Blanc, in Switzerland, being uniformly a little 

 soutli of that mountain peak. 



Ohsermtious of the Thermometer. 



The following table presents a summary of the observations of the thermometer 

 at the several stations. Cohunn first shows the names of the stations ; columns 

 second and third tlieir latitude and longitude ; and column fourth sliows tlie mean 

 tem|)eratnre of each station for the month of December. The mean temperature 

 at noon hr the month of December was obtained by applying to the mean tem- 

 perature of the month a correction deduced from hourly observations at numerous 

 stations in Europe. The mean temperature at noon was subtracted from the 

 observed temperature, and the remainders are given in columns five to twelve. 

 These remainders, therefore, show the number of degrees by wliich the temperature 



