PHILOSOPHICAL SOCIETY OP WASHINGTON. 151 



(45). J. F. Hartgrove, Harper's Ferry, Jefferson County, 

 West Va , lat. 39= 18', long. W. 0° 43'. 

 First seen bearing E. 10° S., rapidly approached the 

 earth, and exploded bearing S. S. W. ? (or S. ?) 

 (46). J. I. Barrick, New Creek (Keyser P. 0.), Mineral 

 County, West Va., lat. 39° 27', long. W. 1° 55'. 

 Observed at 1 h. 42 m. railroad time. First alt. 18'', 



bearing , saw it explode. 



(48), J. L. Gould, Buckhannon, Upshur County, West Va., 

 lat. 38° 56', long. W. 3° 9'. 

 Looking E. observed meteor falling from alt. 60° to 

 alt. 20" or less ; path not vertical, but deflected 8° 

 northward. 



APPENDIX No. IV. 



THE SOUNDS ACCOMPANYING AND FOLLOWING THE METEOR. 



One of the most interesting subjects in connection with such 

 large meteors relates to the sound, as of an explosion, that is 

 frequently observed, and which generally reaches the observer at 

 a considerable interval of time after the body has disappeared 

 from view. 



It is not, however, necessary to assume that an actual explo- 

 sion must have occurred at some portion of the meteor's path. 

 The correct explanation of the phenomenon is undoubtedly found 

 in the fact that, besides the rushing of air and the singing or 

 whizzing of a I'evolving projectile, there is a series of small 

 noises of the nature of explosions, and like the snapping, hissing, 

 and crackling of a wood fire, or soft coal fire, attending the burn- 

 ing of the outer surface of the meteor. 



Owing to the rapid movement of the body, these noises are 

 produced in a few seconds, and, as it were, almost simultaneously, 

 from one end to the other of a line many miles in length. 



Now, if the observer be so situated that the noises from a large 

 portion of the path reach him, almost simultaneously he v;ill 

 hear one loud noise attended by a succession of rapidly dimin- 

 ishing sounds. 



The problem, in fact, is precisely similar to that which has ex- 

 cited so much interest in Optics, namely, as to the effect of the 

 movement of the observer and the source of light upon the 

 apparent color and intensity. 



So far as concerns the acoustic problem, it has been theoreti- 

 cally investigated by Eotvos [Poggendorf, Annalen 1875, clii., 

 p. 535]. 



