here must be at least 13,000 bodies--one in 20,000,000
cubic miles--large enough to make a light visible to the naked eye,
and forty times that number capable of revealing themselves to
telescopic vision. Professor Peirce is about to publish, as the
startling result of his investigations, "that the heat which the
earth receives directly from meteors is the same in amount which it
receives from the sun by radiation, and that the sun receives
five-sixths of its heat from the meteors that fall upon it."

[Illustration: Fig. 49.--Bolides.]

[Page 121]
In 1783 Dr. Schmidt was fortunate enough to have a telescopic view
of a system of bodies which had turned into meteors. These were two
larger bodies followed by several smaller ones, going in parallel
lines till they were extinguished. They probably had been revolving
about each other as worlds and satellites before entering our
atmosphere. It is more than probable that the earth has many such
bodies, too small to be visible, revolving around it as moons.

[Illustration: Fig. 50.--Santa Rosa Aerolite.]

_Aerolites._

Sometimes the bodies are large enough to bear the heat, and the
unconsumed centre comes to the earth. [Page 123] Their velocity has
been lessened by the resisting air, and the excessive heat
diminished. Still, if found soon after their descent, they are too
hot to be handled. These are called aerolites or air-stones. There
was a fall in Iowa, in February, 1875, from which fragments
amounting to five hundred pounds weight were secured. On the evening
of December 21st, 1876, a meteor of unusual size and brilliancy
passed over the states of Kansas, Missouri, Illinois, Indiana, and
Ohio. It was first seen in the western part of Kansas, at an
altitude of about sixty miles. In crossing the State of Missouri it
began to explode, and this breaking up continued while passing
Illinois, Indiana, and Ohio, till it consisted of a large flock of
brilliant balls chasing each other across the sky, the number being
variously estimated at from twenty to one hundred. It was
accompanied by terrific explosions, and was seen along a path of not
less than a thousand miles. When first seen in Kansas, it is said to
have appeared as large as the full moon, and with a train from
twenty-five to one hundred feet long. Another, very similar in
appearance and behavior, passed over a part of the same course in
February, 1879. At Laigle, France, on April 26th, 1803, about one
o'clock in t