OBSERVATIONS OF LUMINOUS METEORS. 313 



fireball was in reality one of a very closely adjacent group or system 

 of ordinary shooting-stars to that observed by Mr. Denning. 



With this observed radiant point the beginning of the meteor's course 

 at Middleton was 82 miles above a point about 8 miles west from Man- 

 chester ; its length, to the point of disappearance is 70 miles, and its 

 duration as estimated by the length of time occupied by the flashes and 

 illumination until the meteor disappeared, was a second and a half, or 

 between two and three seconds, as noted independently by Mr. Greg and 

 Mr. Kay. Some luminous portion of its path was, however, probably 

 traversed by the meteor before the first flash which drew their attention 

 to its descent ; and for the whole length of the course upon which the 

 light-track was traceable which marked its path, a time of flight of about 

 three seconds may fairly be assumed from these descriptions to be rather 

 a somewhat insufficient, than in any degree an over-estimated or 

 exaggerated duration.* The real velocity of the fireball which it gives, 

 is 25 miles per second ; while that of a meteoric body moving with the 

 same radiant point in a cometary or parabolic orbit, would be 21 miles per 

 second — a little less ; implying apparently a small under-estimation of the 

 whole time of flight by about half a second. 



A nearer approach to the theoretical meteor speed could scarcely be 

 expected when the unforeseen and momentary character of the observa- 

 tions is considered, from which by the united evidence of all the 

 particulars of the descriptions the meteor-speed is obliged to be finally 

 determined.* 



The meteor was a very large and vivid one, its light making the 

 smallest objects visible, at Manchester, and its luminous disc having an 

 apparent diameter there of quite one-half that of the moon. It presented 

 two flashes, one previous expansion occurring, before that of its last 

 outburst, which Mr. Greg regarded as much more brilliant, and as having 

 shone from the meteor somewhat before it can have reached the middle 

 point of the above vivid portion of its flight, at a height accordingly of not 



* From Mr. T. Ellison at Colwyn Bay, and Mr. J. E. Walker at Lowcswater, 

 Cockermouth, Mr. Greg and Mr. Clark (vide ' Natural History Journal ' for September, 

 1878) received descriptions of the meteor which show that its end point may have 

 been as far west as 5 or 10 miles off the coast, between Blackpool and Fleetwood, at 

 a height of some 30 miles over the mouth of Morecambe Bay, instead of 20 miles 

 over the Ribble mouth near Preston. The meteor then ended its course at an 

 apparent altitude of 30° or 32°, as seen at both Conway and Loweswater, a little 

 east of their north and south .meridians. The descriptions at those places answer 

 very well to this position, although the recorded altitude (55° or 60°) at Loweswater 

 perhaps refers to the first and brightest portion of the flight, or may have been 

 overrated, as is usual in eye-estimations. — While the direction at Conway is drawn 

 as descending a little obliquely from east towards north, which agrees with the 

 general impression furnished by the other observations, the statement that its course 

 at Loweswater was descending from S. towards S.E., with a slope of 40° from 

 horizontal, or from considerably west of the zenith there, cannot be reconciled with 

 the remaining descriptions, nor even, apparently, with one of the recorded state- 

 ments of its apparent motion at Whitehaven, that "the position of the meteor 

 as seen from that town was about due south, and its course about [? from] north- 

 east." Mr. Walker only saw the end of the meteor's flight askance : but its light- 

 streak of 10° remaining visible for a minute would not allow the discrepancy of his 

 description to be thus explained. From such conflicting data it can only be pro- 

 visionally concluded that the meteor's radiant-point was near the zenith, and that 

 along the line given by the observers' notes of it near Manchester by the stars (Mr. 

 Greg's and Mr. Kay's), it was probably less rather than more than 20° eastward 

 from the zenith. 



