PROFESSOR LOOMIS'S STORM. 291 



Buffalo by the slacking of lime from water driven eastwa'rd 

 by the force of the gale. 



Dr. Franklin first ascertained that all storms travel to- 

 words the north east. 



Mr. Espy's researches led him to believe that this con- 

 stancy of direction in this locality is confined to our winter 

 storms and summer tornadoes. He has also found from ob- 

 servations furnished by Professor Hamilton, that in the 

 winter season, the rise of the barometer, as well as the pre- 

 sence of the centre of the storm, takes place at Nashville, 

 Tennessee, about twenty-four hours earlier than at Phila- 

 delphia. 



And here I would remark, that Dr. Emerson is the first 

 observer, so far as my knowledge extends, who noticed that 

 a great rise of the barometer is a prelude to a north easterly 

 storm, a conclusion to which Mr. Espy has arrived, a priori, 

 from his theory of storms. This conclusion is in direct op- 

 position Jo popular opinion, and, indeed, to that of most 

 philosophers, who have marked set fair on the barometer at 

 one inch above the mean. 



If I mistake not, Mr. Espy has some where stated in his 

 lectures, that remarkable barometric fluctuations were often 

 noticed to occur in the winter season about four or five days 

 later at London than here, indicating that the centre of the 

 storms to which these fluctuations owe their origin, traverse 

 three thousand miles of a rhomb line on the earth's surface 

 in that period of time, being at an average rate of about 

 twenty-two miles per hour. 



If the storm in Pennsylvania, of the 20th and 21st, fol- 

 lowed such a course at that rate, the annulus or atmos- 

 pheric wave which caused the remarkable rise of the ba- 

 rometer here, must have reached London about the 23d or 

 24th, and must have been the harbinger of the approaching 

 storm at that place, the violence of which should be pro- 

 portioned to the excess above the mean of the density of 



