Notice of a Shooting- Star. 21 
stance. This instance, the rare one of an ascending shoot- 
ing-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, the 
author of the paper, who had great faith in his friend’s ex- 
actitude, considered the opportunity favourable for trying 
what results would be given by the application of Sir J. 
Lubbock’s theory. 
Some dissatisfaction has been felt about theories of shoot- 
ing-stars, inasmuch as no one of them will explain a// the 
observed phenomena. But though this is undoubtedly a ne- 
cessary characteristic of a true theory, still great allowances 
are necessary here, where so many different classes of cos- 
mical and atmospherical objects may be confounded even by 
practised observers; and where the greater number of ob- 
servers are utterly unpractised, and their senses wholly un- 
educated for scientific observation. Allowing that some 
electrical and magnetical effects have been mistaken for 
shooting-stars, but excluding the baseless electrical, chemical, 
and lunar hypotheses, a great proportion are undoubtedly of 
a cosmical nature. and belong properly to astronomy ; and 
these may be divided into two classes of small bodies. 1s¢, 
Those which are circulating round the sun as a primary; 
and, 2dly, 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 shooting-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 formule on this supposi- 
tion for computing the distance of the body from the spec- 
tator, by noting the place in the sky where, and the time 
when, the extinction 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 ob- 
servation gives, for the distance of the body from the ob- 
