OBSERVATIONS OF LUMINOUS METEOBS. 275 



110 miles north from Newcastle-on-Tyne, and 75 miles in a direct line 

 from Dunbar, a first outburst of sparks and scintillations (seen at Cal- 

 lander) seems to have taken place, agreeing nearly in its altitude (16°) 

 with the apparent altitude of" 12° or 15° at which it first attracted 

 observers' attention by its unwonted size and luminosity, at Newcastle. 

 It is in the last 60 miles of its path from this point that durations of its 

 flight varying from one-and-a-half to two seconds were noted at Newcastle 

 and at Callander ; while an observer, apparently "of its whole path, near 

 Stranraer, gives four seconds for its duration. Either of these estimates 

 gives nearly 35 miles per second as its real speed of flight. The radiant 

 point was at 332° — 20° (R.A. and Decl.), and the speed of a meteor from 

 this radiant point with a parabolic orbit is 33 miles per second ; a velocity 

 which the observations therefore substantiate very nearly. Measurements 

 of the meteor's course at two places near Callander, and at two places 

 near Newcastle-on-Tyne, as pointed out by observers there, were obtained 

 by Professor Herschel, and corroborated each other at those places within 

 a few degrees. In answer to a request for similar measurements addressed 

 to observers of the fireball in the ' Scotsman ' of May 1st, by Professor 

 Herschel, a very exact description of its apparent path by carefully 

 observed positions of the line of light, or cloud-streak left upon its track, 

 at Coupar Angus, 15 miles N.W. from Dundee, was sent to the Committee 

 by the head railway porter of that station, Mr. John Robertson. And good 

 accounts of its course at Wigton and Hawick, in the south-west part of 

 Scotland, and at Darlington, as a more distant point of observation in 

 England, were also recorded, of which the collected statements carefully 

 compared together, combine to fix with considerable certainty, and with a 

 degree of accuracy which only admits of very small corrections, the 

 height and situation, and the real direction and velocity, of the meteor's 

 course, as above described. A peal of distant thunder, heard at about the 

 time of the meteor's appearance at Dunbar, is perhaps attributable to it, 

 though the distance of the nearest point of the meteor's track was there 

 70 miles, which sound traverses in five minutes and a half ; and throughout 

 its course it was indeed between 50 and 70 miles distant from all the 

 easternmost points of the coast, and from the principal towns of the east 

 part of Scotland, where it was very widely noted and observed. 



The real direction of this fireball's motion round the sun and arrival 

 upon the earth is remarkable, as but little below the ecliptic (about 9°), 

 very nearly at the place which would belong to the path of a body 

 projected with parabolic velocity directly from the sun itself. In its real 

 orbit it approached the earth from a point of the heavens within 10° of 

 the sun's place (about 3° behind it in longitude, and 9° south of it in 

 latitude), which was in the ecliptic at longitude 4^°. The following table 

 gives the elements of its orbit, supposing it to have been parabolic : and 

 the conclusion arrived at from the observations is that the perihelion 

 distance, or the least distance of the meteor in its orbit from the sun's 

 centre during its closest approach to and passage round the sun, was 

 about ^th (0 - 022) of the earth's distance from the sun, or about four of 

 the sun's radii distant from its surface as it neared it, and made the rapid 

 circuit of its sharply returning orbit round it ! 



ffi = 184° 30' "1 



^ Z 70 \ Motion retrograde. 



q = 0022 J 



t2 



