152. REPORT—1857. 
A large meteor observed at Wilton was estimated by Mr. E. C. Herrick 
(Am. Journ. of Science, vol. xxxvii. p. 150) to be about 150 feet in diameter, 
It appeared to increase gradually in size until just before the explosion, when 
it was at its largest apparent magnitude of 1 the moon's disk: exploded at 
25° or 30° altitude with a heavy report, which was heard 30 seconds after 
the explosion was seen. One or more of the observers saw fragments descend 
to the ground. When it exploded it was three or four miles from the surface 
of the earth ; immediately after the explosion it was no longer visible. The 
large size of the body is inferred from the fact of its appearing 3 of the moon’s 
diameter about six miles’ distance. 
After the experiments above recorded, the uncertainty of such a con- 
clusion is evident. A body in a state of incandescence might exhibit the 
apparent diameter of the Wilton meteor at six miles’ distance and not be 
more than a few inches or a foot in actual size, according to the intensity of 
the incandescence. 
It ought to be added that Mr. Herrick (in the paper referred to) expressly 
allows for some uncertainty of this kind. 
The author further instances another large meteor observed at Weston, 
and estimated by the same kind of calculation at a mile and a half in dia- 
meter: on the principle of these experiments it need not have been more than 
one or two feet. 
No. 6.—Extract of a Notice of a Shooting Star, by Prof. C. Piazzi Smyth. 
From the Proceedings of the Royal Society of Edinburgh, No. 34, Feb. 5, 
1849. 
This instance, the rare one of an ascending shooting star, was furnished 
by Captain W. S. Jacob, Bombay Engineers ; and he having given the place 
where the body first appeared, that where it disappeared, and the time, with 
great exactness, it was considered by the author to afford a good case for 
testing the theory of Sir J. Lubbock. 
Allowing that many phenomena of an atmospheric kind may have been 
confounded with true shooting stars, still, the author observes, a great pro- 
portion are undoubtedly of a cosmical nature, and belong properly to astro- 
nomy ; and these may be divided into two classes of small bodies. Ist, Those 
which are circulating round the sun as a primary; and, 2ndly, Those which 
are revolving round the earth as such. ‘The first we may occasionally see 
when passing near them in their orbits, but are not likely to come within 
sight of the same again, unless, indeed, they approach so near the earth as 
to gravitate towards it instead of the sun, and so become satellites or shoot- 
ing stars of the second class. 
Sir J. Lubbock’s theory is, that the shooting stars shine by reflected light, 
and are extinguished by entering the earth’s shadow; and he has given for- 
mulz on this supposition for computing the distance of the body from the 
spectator by noting the place in the sky where, and the time when, the ex- 
tinction occurs. 
These formule have been rendered more convenient for computation by 
Mr. Archibald Smith, Phil. Mag., March 1849; and, computed according 
to them, Captain Jacob’s observation gives, for the distance of the body from 
the observer, 1721 miles: and that entry into the earth’s shadow was the 
true cause of the disappearance, is borne out by the fact that the direction 
of motion was towards the axis of the earth’s shadow. And, on account of 
the extremely small distance of the body, its change of place during flight 
would sufficiently account for its gradually appearing in the lower part of 
the sky when coming out of conjunction, increasing in brilliancy during its 
ee ee 
athe. ? 
