REPORT OF THE SECRETARY. 31 



least forty-eight Lours, indicating' an ascending current of air and a 

 tendency to rotation contrary to the motion of the hands of a watch. 



The author next proceeds to offer some suggestions as to the origin 

 of the storm, which in the main agree with the exposition of the phe- 

 nomena as given in the theory of Espy, namely, the upward motion 

 of the air at the point of lowest barometer, the evolution of latent 

 heat by the condensation of the vapor which it contains, and the 

 transfer eastward of the whole disturbance by the flow of the upper 

 current in that direction. He attributes the principal cause of the 

 cold experienced to the upper current descending to the surface of 

 the earth. 



The European storm of the 25th of December of the same vear is 

 investigated in the same manner, and the results illustrated by means 

 of eight separate maps, one for each day, commencing with Decem- 

 ber 21, including the beginning and ending of the disturbance. It 

 was at first supposed that this storm was a continuation of that of the 

 20th experienced in America; the rate of progress, however, of the 

 latter was such that it could not have reached Europe before the 

 27th, whereas the storm of the 25th was fully organized on the 23d, 

 and, indeed, its first movements can be distinctly traced in Germany 

 on the 22d. The European storm evidently originated in Europe, 

 and the American storm wasted itself in the Atlantic. It was, 

 however, the possible connexion of these two storms that induced 

 Professor Loomis to collect particularly, during a visit to Europe in 

 185G— '57, records of meteorological observations for this period. The 

 whole number of stations from which he obtained data was nearly 

 fifty. 



It was mentioned in the last report that the Institution had con- 

 cluded to publish in full detail several series of meteorological obser- 

 vations made for long periods in different parts of the United States. 



The 12th volume of Contributions will contain the first of these 

 series, by Professor A. Caswell, of Brown University. The observa- 

 tions commence with December 1, 1831, and end with December 31, 

 1859,*" including a period of a little more than twenty-eight years. 



These observations were made three times daily, embracing the 

 thermometer, barometer, the direction and force of the wind, the 



s These tables have been extended to June, 18G0. 



