LABORS OF THE JOINT COMMITTEE. 85 



responds well with the fluctuations of the barometer men- 

 tioned before. 



It may be mentioned, also, that, reckoning from middle 

 to middle of the storm, it was thirty and a half hours from 

 Nashville to Middletown, and thirty-two and a half from 

 Nashville to Portsmouth. These all agree in giving a velo- 

 city to this storm of about twenty-six miles an hour. Is this 

 the velocity of the upper current of air at Philadelphia, which 

 comes generally from a point south of west ? Is it this 

 zipper current which gives direction to the storms in this lati- 

 tude ? 



Many instances have been observed upon a momentary 

 breaking of the lower clouds, in the very middle of these 

 north east storms, when the clouds above were coming from 

 south west. 



This storm had a north east and south west diameter, at 

 Nashville, of about two hundred miles, gradually increas- 

 ing in size until, at Portsmouth, it was eight hundred miles. 

 Its north west and south east diameter is unknown. 1 



What are these two diameters of storms generally ? 



Our correspondents will perceive that something on this 

 subject is likely to be discovered by a persevering course of 

 simultaneous observations over our wide extended conti- 

 nent. The Joint Committee which now addresses you will 

 spare no means to elicit from your observations, decisive 

 answers to the queries proposed above, and, if possible, to 

 establish such general laws as will entitle meteorology to 

 the name of science. 



To this end, it is essential that the original observations, 

 and not the mean of several, should be communicated, and 

 that the number and extent of our correspondents should 

 be increased ; we therefore request each one of our corres- 

 pondents to procure at least two more. It would be very 



J Much more on this subject is known now, as will be seen hereafter. 



