Intelligence and Miscellaneous Articles, 157 



the Earth's orbit and that of the orbit of the meteors projected on 

 the ecliptic, while the actual small angle so included, of 0° 45' only, 

 indicates a very near (possibly an exact) coincidence of direction. 

 Hence we are constrained to conclude that the true line of direction 

 in space of each meteor's flight lay in a plane at right angles to the 

 Earth's radius vector at the moment, and that therefore, except on 

 the improbable assumption that the meteor was at that moment in 

 perihelio or in aphelio, its orbit would not deviate greatly from the 

 circular form. The absolute velocity in space of the meteors would 

 therefore be nearly that of the Earth ; and from this it appears to 

 follow of necessity that the direction of their revolution must be 

 retrograde. Were it direct, the relative motion parallel to the 

 ecliptic would be nil, and the only effective cause of apparent motion 

 would be the meteor's resolved velocity perpendicular to the ecliptic, 

 which would produce a radiant in the pole of the ecliptic. 



In point of fact the elevation of the radiant above the ecliptic was 

 only 10° 15'; and as the relative velocity of the meteors in a direc- 

 tion parallel to the latter plane must have been twice the Earth's 

 absolute velocity, it follows that, had the Earth stood still, the then 

 apparent radiant would have had very nearly double that elevation 

 (more correctly, 19° 53'), which is therefore the inclination to the 

 ecliptic of the meteoric orbits. 



How far this conclusion of a retrograde motion of the meteorite's 

 revolution round the Sun — a conclusion already, I believe, arrived 

 at by Mr. Newton — is compatible with the truth of the " Nebular 

 hypothesis," we may leave it to the advocates of that hypothesis to 

 consider. 



I have mentioned the case of one of the meteors leaving a train 

 visible during 2 m 40 s . A much more striking instance occurred 

 in the case of one which exploded close to the three bright stars 

 in Aries. The train left at first w T as very bright, and very nearly 

 parallel to the line joining a and /3. It remained visible for no 

 less than 6 minutes, during which time it drifted slowly to the 

 southwards over a space of 8 or 9 degrees, and at the same time gra- 

 dually changed its direction, so that just before its disappearance it was 

 at right angles to its original position. — Monthly Notices of the Royal 

 Astronomical Society, December 14, 1866. 



INFERENCE PROM THE OBSERVED MOVEMENT OF THE METEORS 

 IN THE APPEARANCE OF 1866, NOVEMBER 13-14. BY G. B. 

 AIRY, ESQ., ASTRONOMER ROYAL. 



It is established by abundant evidence that the meteors seen in 

 the late magnificent display diverged, for the most part, with singular 

 accuracy, from a point which may thus be described : join y Leonis 

 and e Leonis by an arc of a circle, the centre of divergence was 

 about a degree north of the middle of the arc. There were other 

 centres of partial radiations, but this may be accepted as the centre 

 of radiation of the general mass. 



This was the case all through the night. In fact, the first exact 



