296 Recent contributions to Astro-Meteorology. 
occurs in these crystallizations we are even led to think that such a form 
of aggregation is much more probable and more frequent than the others, 
which take place by large masses. Hence the volume occupied by the 
cosmical clouds may be a notable fraction of the stellar space. 
“III, The movements of such clouds among the bodies of the universe, 
are comparable to those of the fixed stars, and are probably due to analo- 
gous causes. When any one of them enters the sphere of attraction of the 
sun, it cannot be visible to us unless its orbit relative to this great Jumi- 
nary is a very greatly elongated conic section. 
‘IV. Whatever may be the form and extent of a cosmical cloud, ‘it 
cannot (with very rare exceptions) penetrate to the interior of the solar 
system, unless it has been transformed into a parabolic current, which 
May consume years, centuries, and myriads of years in passing, part by 
r i 
are encountered by the earth in its annual motion, are rendered visible: 
to us under the form of showers of meteors diverging from a certain 
radiant. 
mations in space, like rivers which slowly change their bed. They may 
be interrupted, and thence become double or multiple, and they may even 
in particular circumstances become closed elliptical rings. The Novem- 
ber meteoroids are apparently portions of such a ring in process of for- 
mation. 
“VI. The cosmical clouds having short periods of revolution around the 
sun, by which some are inclined to explain the appearance of shooting 
annot have a permanent existence without violating the known 
laws of universal gravitation, 
“VIL The matter of the parabolic currents, after having passed the 
perihelion, returns into space in a state of dispersion, greater than that 
which it had before the passage. In particular cases, as when the cur- 
rent meets a planet, very great perturbations may ensue, and a separation 
of some of the meteoric stars into special orbits. Such stars from that 
moment may be called truly sporadic 
“ IX. Since we may safely regard it as certain that falling stars, bolides, 
and aérolites differ in nothing except their magnitude, we may conclude 
