ORBIT AND PHENOMENA OF A METEOEIC FIRE-BALL, 



WHICH PASSED OVER PORTIONS OF THE UNITED STATES AND CANADA, ON THE 20TH OF JULY, 1860. 



On the evening of July 20th, 1860, a meteoric fire-ball passed over the northern 

 parts of the United States and the adjacent parts of Canada, of so extraordinary 

 brilliancy as to attract the attention of numerous observers along its entire visible 

 track of nearly or quite 1300 miles, and on either side of it to the distance of 

 several hundred miles. It was reported to have been first seen moving eastward 

 from a point nearly over the western shore of Lake Michigan, though it not improb- 

 ably became luminous when it was somewhat further west, as the sky over all that 

 region was obscured by clouds, and it was not till the meteor had reached a point 

 some 150 miles further east that the first reliable determination of its position was 

 made. From thence many eyes watched its course till it disappeared quite out at 

 sea in a southeasterly direction from the island of Nantucket. 



From the following series of observations, obtained partly from the newspapers 

 of the time, partly through the co-operation of scientific friends, who, at the request 

 of the writer, kindly made inquiries in regard to the phenomenon in their respective 

 localities, or measurements of the meteor's position, as estimated by themselves or 

 pointed out by those who saw it ; and partly from collections kindly put into his 

 hands for the purpose by the Smithsonian Institution, and by Profs. Lyman and 

 Newton, of Yale College, an attempt has been made to determine the elements of 

 its orbit or path.^ At a few of the places, where estimates of the meteor's altitude 

 at special azimuths were desired, and where the proper instruments for this mea- 

 surement were not at hand, estimates were made by a sort of extemporized quad- 

 rant in the following manner, which, for the sake of brevity, is designated in the 

 following series as the " card method." From a point in a line drawn upon a card 

 (or sheet of paper attached to a piece of board), a small weight was suspended by a 

 string, and the card being held in a vertical position, and the line directed toward 

 the estimated place of the meteor, when it was at the specified azimuth, the position 

 of the string was noted, as it rested against the card, and a line drawn upon the 



' In making the computations, valuable aid was contributed by Mr. Benjamin P. Stem, A. M. a 

 gentleman of superior mathematical attainments; by my son, Seldcn J. Coffin, A.M., and by Messrs. 

 W. P. Montelius and A. P. Reid, members of the Senior Class in Lafayette College. 



1 January, 1869. f 1 \ 



