“The stars and the mailed moon,
     Though they seem to fall and die,
   Still sweep in their embattled lines
     An endless reach of sky.

  “And though the hills of Death
     May hide the bright array,
   The marshalled brotherhood of souls
     Still keeps its onward way.

“Upward, forever upward,
I see their march sublime,
And hear the glorious music
Of the conquerors of Time.

“And long let me remember
That the palest fainting one
May to diviner vision be
A bright and blazing sun.”

THOMAS BUCHANAN READ.

[Page 117] VII.

SHOOTING-STARS, METEORS, AND COMETS.

“The Lord cast down great stones from heaven upon them unto Azekah, and they died.”—­Joshua x.  II.

[Page 118] [Illustration:  A SWARM OF METEORS MEETING THE EARTH.

Their orbits are all parallel.  Those coming in direct line to the eye appear as stars, having no motion.  Those on one side of this line are seen in foreshortened perspective.  Those furthest from the centre, other things being equal, appear longest.  The centre, called the radiant point, of these November meteors is situated in Leo; that of the August meteors in Perseus.  Over fifty such radiant points have been discovered.  Over 30,000 meteors have been visible in an hour.]

[Page 119] VII.

SHOOTING-STARS, METEORS, AND COMETS.

Before particularly considering the larger aggregations of matter called planets or worlds as individuals, it is best to investigate a part of the solar system consisting of smaller collections of matter scattered everywhere through space.  They are of various densities, from a cloudlet of rarest gas to solid rock; of various sizes, from a grain’s weight to little worlds; of various relations to each other, from independent individuality to related streams millions of miles long.  When they become visible they are called shooting-stars, which are evanescent star-points darting through the upper air, leaving for an instant a brilliant train; meteors, sudden lights, having a discernible diameter, passing over a large extent of country, often exploding with violence (Fig. 48), and throwing down upon the earth aerolites; and comets, vast extents of ghostly light, that come we know not whence and go we know not whither.  All these forms of matter are governed by the same laws as the worlds, and are an integral part of the solar system—­a part of the unity of the universe.

[Illustration:  Fig. 48.—­Explosion of a Bolide.]