k 
ts 
: 

NEBULA LATELY OBSERVED IN THE S1X-FEET REFLECTOR. 53. 
relative positions, especially with respect to the earth. Taking Lacerta as 
the middle point of the path of a No. 1, the head of Cepheus as that of 
a No. 6 and ¢ Bootes as that of 6 No. 1, it is very evident that the earth, or at 
least its centre, must have passed considerably to the south of the plane 
passing through the centres of a No. 6 and 6 No. 1, and as 6 No.1 appeared 
but a few minutes after a No. 6, the distance between them would be con- 
_ siderably less than that between a No. 1 and either of the others. If, as has 
been suggested, the direction of the earth’s motion was such as to leave the 
meteor 6 No. 1 on the north and a No. 6 on the south, both would be suf- 
ficiently identifiable at any part of the earth’s surface from which they might 
be visible :—1st, from the priority of the southern meteor ; and 2nd, from the 
apparent opposition of their motions; and should observations have been 
made from which the altitudes of each above the earth’s surface may be 
deduced, it would not be very difficult to determine approximately and 
within certain limits their distance from each other, due allowance being 
made for the earth’s motion between the instants of apparition. In connexion 
with the view here taken of the relative positions of these three bodies, the 
straightness of their paths strongly indicates the passage of the earth past 
them. Upon M. Quetelet’s determination of the mean altitude of these 
bodies being sixteen or twenty leagues, it would appear that when the nearest 
point of the earth’s surface approaches a meteoric body at or within this 
distance, the phenomena witnessed would be produced: the body would 
pass through a segment of the earth’s atmosphere, the path most probably 
differing but little from a straight line; upon entering the earth’s atmosphere 
combustion may take place, as suggested by Prof. Powell, and this may give 
rise_to the reddish scintillations so apparent in the three bodies observed ; 
these scintillations presented phenomena perfectly in accordance with this 
notion, being most intense in the middle or deepest part of the earth’s atmo- 
sphere, and gradually dying off at each extremity. 
_ The meteors 5 Nos. 4 and 5 appeared to be essentially different from the 
three we have just noticed; the well-defined globular appearance they 
presented, the comparative slowness of their motion, the slight curvature of 
their paths, and their decided increase of brilliancy just previous to their 
extinction, place them altogether in a different category, and would lead one 
to expect that at more southern stations they appeared both larger and more 
brilliant. It would be interesting to obtain observations of these meteors 
(which certainly were unmistakeable in their character) from places at which 
they were vertical. At present however we must be content with knowing 
_ that of the group of meteors observed they were probably the most southern, 
the plane of their motion being less inclined to the ecliptic than to the 
— equinoctial. 
Notice of Nebule lately observed in the Six-feet Reflector. By the 
- Earu or Rosse, Pres. R.S. Communicated by the Rev. Dr. 
_ Robinson, Pres. B.A., and ordered to be printed entire among the 
vb Reports. 
Ar the Meeting of the British Association at York in 1844, it was an- 
nounced that a reflecting telescope of six-feet aperture, which had been 
about two years in progress, was nearly completed, and some slight account 
‘was at the same time given of the means which had been taken to render the 
instrument convenient and effective. A short notice of the principal results 
