Fire-balls observed in Pennsylvania, in 1819. 115 



horizon: it travelled, whilst within view here, about 120° in 

 the heavens, and that in a period of not less than five, nor 

 more than ten seconds; beginning to decline in brilliancy 

 when at about 30° below the zenith, and in two seconds be- 

 coming invisible, at 30° above the western horizon ; its tail, 

 in the mean time, lengthening to 10° or 15°, forming a nar- 

 row red streak of evanescent fire. Mr. Turney states it to 

 have passed through his hemisphere in a very few seconds ; 

 and near Easton, where a sound was heard in its direction. 

 It suddenly disappeared from him at about the altitude of 40°, 

 in the south or south-west. About three minutes after its dis- 

 appearance, says the Editor of the American Watchman, a 

 noise was heard resembling the discharge of cannon, or distant 

 thunder, and in a westerly direction : after the lapse of two, 

 three, or four minutes, Mr. Turney observes, two reports were 

 heard, the sound continuing for many seconds. 



By comparing the observations made by various persons in 

 different situations, Mr. Turney estimated the height of this 

 meteor to have been at least twenty miles : and taking its ap- 

 parent diameter at one-third of the moon's, he computes its 

 actual diameter at more than one hundred yards. The na- 

 ture of the observations from which the height was determined 

 is not stated ; but such vague estimates of the apparent mag- 

 nitude of a luminous body in rapid motion as those above 

 given, are evidently insufficient for a near approximation to 

 its actual size. The sound heard at Easton, Mr. T. thinks, 

 could not have been the same with that heard at his station, 

 " which came from a point not less than thirty miles to the 

 south ;" whence he infers, " that the body must have been 

 ignited a second time." This supposition, however, appears 

 to me to be unnecessary; for the sound heard in the direction 

 of the meteor at Easton probably arose from the velocity of 

 its passage through the atmosphere : thus, a whizzing sound 

 like that of a bomb traversing the air, together with a crack- 

 ling noise, was produced in its flight by the meteor which 

 threw down a stone at Sales, near Villefranche, March 12, 

 1798 ; also by that observed at Geneva, May 15, 1811, which 

 has been described by Professors Pictet and Prevost ; as well 

 as by several others. 



Mr. Turney, in agreement with the view of the nature of 

 these phaenomena which has within these few years become 

 very general amongst scientific men, and which, perhaps, is 

 the most satisfactory hitherto proposed, terms the meteor just 

 described a terrestrial comet; and suggests that it may be the 

 same with that which passed over Connecticut and cast down 

 a shower of stones in 1807, its course being nearly the same. 

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