290 PHILOSOPHY OF STORMS. 



nected with the no less remarkable storm that traversed 

 Pennsylvania on the evening of the 20th and morning of 

 the 21st of the same month. 



The approach of that storm was announced by the chair- 

 rnan of the Joint Committee on Meteorology of the Philo- 

 sophical Society, and the Franklin Institute of Pennsyl- 

 vania, at their session on Monday evening, the 19th Decem- 

 ber. The substance of Mr. Espy's communication was, 

 that on a reference to the observations of Governeur Erner- 

 sori, M. D., and his own, it appeared that the barometer had 

 risen during the last twenty-four hours 1.05 of an inch ; 

 that it attained its maximum height at seven, P. M., arid 

 was then, at eight, P. M., beginning to descend; that such 

 a rise of the barometer had not been observed in the same 

 period of time for several years ; that this and other phe- 

 nomena noticed at the time induced him to think that we 

 were then in the eastern part of the annulus or border of a 

 violent storm ; that though perfectly clear and calm at that 

 time, it was reasonable to expect that the wind would set in 

 from the east next morning ; that in such a case it would 

 be certain that in twenty-four hours, that is to say, by the 

 evening of the 20th, the storm would reach this place, and 

 would rage with a violence proportioned to the extraordinary 

 rise of the barometer which preceded it ; that the deposit 

 of snow or rain, would, for the same reason, be very great. 



For proof that the prediction was fully realized, 1 refer 

 you to the account published in the journals of that date. 

 The wind changed to the east next morning, the 20th, and 

 the rain at this place, and snow further north, commenced 

 falling on the evening of the same day, and closed on the 

 morning of the 21st. Serious damage was done to the ship- 

 ping in the Delaware, and at all our north eastern ports, 

 and off the coast. At Buffalo, the wind drove a portion of 

 the water of Lake Erie into the city, and it was stated in 'the 

 gazettes of that date, that a building was set on fire at 



