﻿220 Miscellanies. 



Passage of the perihelion, September, 1844, 2-519608 

 Longitude of the perihelion, 

 Longitude of the ascending node, 

 Inclination, .... 



342° 31' 55 '5 



63° 48' 56' 



2° 53' 66"-6 



0-6092118 



3.0306258 



1- 1843330 



•5 \ Mean equi- 



n I noxof Sept. 

 •6 ) 1, 1644. 



Eccentricity, .... 



Half the larger axis, . 



Distance of the perihelion, 



Time of the revolution 5 years, 3 months, 10 days. 



8. Note from Dr. Hare, correcting an error in his Strictures on 



Prof. Dove's Law of Storms. 



Philadelphia, Nov. 23, 1844. 



Messrs. Editors — I beg leave to correct an error committed in my 

 strictures on Dove's Law of Storms, in assuming that the contents of 

 the zones comprised in the same circle between equidistant concentric 

 parallel lines, are to each other as the squares of their mean distances 

 from the common centre ; instead of assuming them to be simply as 

 those distances. Of course the velocity of the air in the zone nearest 

 the upward columnar current, in a tornado or hurricane, will not be to 

 the velocity of any greater zone, inversely as the squares of the mean 

 distances from the axis of the column ; but simply in the inverse ratio 

 of those distances. 



Hence, supposing the centripetal velocity at a mile from the centre, 

 to be one hundred miles per hour, at twenty miles it would be five 

 miles per hour, or merely a breeze. By this amendment of the cal- 

 culation my argument is strengthened, so far as it was an object of it to 

 prove, that in an extensive hurricane the central area, protected by the 

 upward current from the horizontal impetus of the wind, and conse- 

 quently calm, need not be so spacious as to require more than a very 

 few minutes for it to be passed over by a storm travelling at the rate 

 of thirty miles per hour. 



Supposing the wind to blow only from two opposite quadrants, as in 

 the storm of December, 1836, it would of necessity make the distance 

 at which the wind would be reduced to a breeze of five miles per hour, 

 twice as great as that above mentioned.* I am, gentlemen, very sin- 

 cerely yours, Robert Hare. 



9. A new Medical Periodical, to be called " The Southern Journal 

 of Medicine and Pharmacy," is about to be published monthly in Charles- 

 ton, S. C, edited by J. Lawrence Smith, ML D. and S. D. Skinner, M. D., 

 aided by many able collaborators. The price of subscription is 84 per 

 annum, in advance. 



* See Memoir of Prof. Loomis in the American Philosophical Transactions. 



