80 REPORT — 1879. 



was appointed immediately after the occurrence of this unusually large 

 fireball to collect accounts of its appearance, and to submit them to a 

 scientific discussion. Professor Cleveland Abbe, the Secretary of the 

 Committee, describes in this Report l the delay which arose in its publi- 

 cation from the conflicting nature of the particulars furnished by observers 

 of the meteor in tbe different accounts, together with a hope that a search 

 conducted near the point of disruption of the meteor which these accounts 

 had fairly established by the enquiries during the year 1874, might be 

 rewarded by the discovery of some fragments of its substance. But this 

 hope not having during the following three years been realised, the 

 Report containing the observations and some results of their comparison 

 together has no longer been withheld. 



The fireball passed from about N.E. to SW. nearly over "Washington, 

 with an intense illumination of the streets and houses of the town 

 to a point so near the horizon (not more than 5° altitude), as in general 

 to have been lost sight of behind buildings while still continuing its 

 course. Professor Holden observed the terminal point at the U.S. Naval 

 Observatory at altitude 4°45', 22° S. from W. Accounts of its first 

 appearance at Washington are much less certain and precise. Professors 

 Newton, Hilgard, and Baird heard the explosion indoors at an interval 

 after the light-flash which they noted variously as 1^—3 minutes, 

 corresponding to a distance of the meteor's track, at its nearest point, of 

 18 to 36 miles from Washington. The explosion was a ' bang ' or loud 

 report, shaking doors, windows, and the earth, followed for 20 s or 30 s by 

 a roar or rustling sound which died gradually away. Professor Abbe 

 explains (in the manner theoretically investigated by Eotvos, Pog- 

 gendorff's 'Annals,' 1874, clii., p. 513) that the sudden clap of a 

 meteoric detonation is probably not caused by the final disruption, but 

 by the combined impulse of all the sound-waves reaching an observer's 

 station from the long tract of the meteor's roaring passage through the 

 air which is nearest to him, and from which all the sound reaches him 

 almost simultaneously, while a prolonged roll, like echoes of the first 

 sound, is afterwards heard from more distant portions of the meteor's 

 track. 



Accounts at Centreville and other places in Fairfax County, 30 or 40 

 miles W. a little S. from Washington, that the final explosion there was 

 nearly overhead, approximately fix the meteor's end-point, which must, 

 if not more distant from Washington, have been at the low height of not 

 more than two or three miles above the earth to satisfy the observed 

 altitude at Washington of its final disappearance. It seems more probable, 

 as Professor Chickering has endeavoured to show from more distant observa- 

 tions, that the meteor's flight was continued considerably beyond Fairfax 

 County, and that its final height (estimated at 20 miles by Professor 

 Chickering) was not less than 10 miles over a point some 60 or 70 miles 

 from Washington. The height and position of the remainder of the course 

 are somewhat variously defined by a great number of distant observations 

 at Danbury, Conn. (250 miles N.E. from Washington), at Newark, 

 Delaware, where its commencement was nearly overhead, at Westminster, 

 Mercersburgh, Baltimore, and other towns in Maryland, and at Richmond 

 and Appomatox Court House in Virginia. The slope of its path in the 



1 By a Committee consisting of Hon. Peter Parker, W. L. Nicholson, and Cleveland 

 Abbe, ' Bulletin of the Philosophical Society of Washington,' vol. ii. p. 139 ; April 7, 

 1877. -Excerpt of 22 pp., with a map by W. L. Nicholson ; from the authors. 



