552 Royal Astronomical Society. 



trary to every analogy of the solar system. Fourthly, if masses of 

 solid matter approached so near the earth as many of the shooting- 

 stars do, some of them would inevitably be attracted to it ; but of 

 the thousands of shooting-stars which have been observed, there is 

 no authenticated instance of any one having actually reached the 

 earth. Fifthly, instead of the meteors being attracted to the earth, 

 some of them are observed actually to rise upwards, and to describe 

 orbits which are convex towards the earth ; a circumstance, of which, 

 on the present hypothesis, it seems difficult to give any rational 

 explanation. 



5. The most recent hypothesis is that of Capocci of Naples, who 

 regards the aurora borealis, shooting-stars, aerolites, and comets, as 

 having all the same origin, and as resulting from the aggregation of 

 cosmical atoms, brought into union by magnetic attraction. He 

 supposes that in the planetary spaces there exist bands or zones of 

 nebulous particles, more or less fine, and endued with magnetic 

 forces, which the earth traverses in its annual revolution ; that the 

 smallest and most impalpable of these particles are occasionally pre- 

 cipitated on the magnetic poles of our globe, and form polar auroras ; 

 that the particles a degree larger, in which the force of gravitation 

 begins to be manifested, are attracted by the earth and appear as 

 shooting-stars ; that the particles in a more advanced state of con- 

 cretion give rise in like manner to the phenomena of fire-balls, 

 aerolites, &c. ; that the Comets, which are known to have very small 

 masses, are nothing else than the largest of the aerolites, or rather, 

 uranolites, which in course of time collect a sufficient quantity of 

 matter to be visible from the earth. This theory of Capocci differs 

 from Chladni's only by the introduction of magnetic forces among 

 the particles, and it is obvious that all the objections to the former 

 theory apply with equal force to this. It may be remarked, how- 

 ever, that some physical connexion between the phenomena of 

 shooting- stars and aurora had been already suspected, and the 

 observations adduced by M. Quetelet afford reason to suppose that 

 the latter phenomenon is also periodical. 



From the difficulties attending every hypothesis which has hitherto 

 been proposed, it may be inferred how very little real knowledge 

 has yet been obtained respecting the nature of the shooting-stars. 

 It is certain that they appear at great altitudes above the earth, and 

 that they move with prodigious velocity ; but everything else re- 

 specting them is involved in profound mystery. From the whole of 

 the facts M. Wartmann thinks that the most rational conclusion we 

 can adopt is, that the meteors probably owe their origin to the 

 disengagement of electricity, or of some analogous matter, which 

 takes place in the celestial regions on every occasion in which the 

 conditions necessary for the production of the phenomena are re- 

 newed. 



The concluding part of the paper contains an account of the dif- 

 ferent attempts which have been made to deduce differences of longi- 

 tude from the observation of shooting- stars. That meteors which 

 appear and are extinguished so suddenly, and which by reason of 



