195 



Thomas Y. Simons, M. D., Chairman of the Board. — From the 

 same. 



The Committee, consisting of Professor Bache, Dr. Patter- 

 son, and Mr. Walker, to whom was referred a paper entitled 

 " On the Storm which was experienced throughout the United 

 States, about the 20th of December, 1836, by Elias Loomis, 

 Professor of Mathematics and Natural Philosophy in Western 

 Reserve College," reported in favour of publication in the So- 

 ciety's Transactions, which was ordered accordingly. 



The memoir of Prof. Loomis first describes the sources of informa- 

 tion to which he has had access, consisting of various published or 

 private meteorological journals. The principal phenomena occurred in 

 the eastern states, within the period recommended by Sir John Her- 

 schell for hourly meteorological observations ; and were, of course, 

 accurately noted at the stations where these observations were made. 

 From various sources, Prof. Loomis has obtained observations of the 

 barometer at twenty-seven different stations in the United States and 

 the neighbouring British possessions, and records of the thermometer 

 and weather from twenty-eight military stations of the United States, 

 from forty-two academies of the state of New York, and from five 

 other stations within the probable limits of the storm, besides others 

 beyond it. In some cases two sets of observations were made at the 

 same station. 



The phenomena are discussed by the author under the following 

 heads. 1. A remarkable oscillation of the barometer. 2. A sudden 

 depression of the thermometer. 3. The amount, and the time of be- 

 ginning and ending of the rain. 4. The direction and velocity of the 

 wind. 



1. The observations of the barometer show that during the storm 

 there was a sudden depression of the barometer immediately suc- 

 ceeded by a sudden rise; that the minimum of pressure occurred 

 first in the western states, and passed in a wave over the United States, 

 moving eastwardly. The curves drawn to represent the heights of 

 the barometer illustrate this fact in a very striking manner. Prof. 

 Loomis has attempted to determine, from the observations, the 

 amount of depression of the barometer, the form and velocity of the 

 atmospheric wave, the progress of which, over the United States, he 

 has represented upon a chart. 

 c 



