on is more
particularly obvious. Even the nucleus is not solid, and is often
transparent.

It is fair to say that the action of a comet might be deleterious if one
of these orbs were to arrive directly upon us. The transformation of
motion into heat, and the combination of the cometary gases with the
oxygen of our atmosphere might produce a conflagration, or a general
poisoning of the atmosphere.

But the collision of a comet with a planet is almost an impossibility.
This phenomenon could only occur if the comet crossed the planetary
orbit at the exact moment at which the planet was passing. When we
think of the immensity of space, of the extraordinary length of way
traversed by a world in its annual journey round the Sun, and the speed
of its rotation, we see why this coincidence is hardly likely to occur.
Thus, among the hundreds of comets catalogued, a few only cut the
terrestrial orbit. One of them, that of 1832, traversed the path of our
globe in the nights of October 29 and 30 in that year; but the Earth
only passed the same point thirty days later, and at the critical period
was more than 80,000,000 kilometers (50,000,000 miles) away from the
comet.

On June 30, 1861, however, the Earth passed through the extremity of the
tail of the Great Comet of that year. No one even noticed it. The
effects were doubtless quite immaterial.

In 1872 we were to collide with Biela's Comet, lost since 1852; now, as
we shall presently see, we came with flying colors out of that
disagreeable situation, because the comet had disintegrated, and was
reduced to powder. So we may sleep in peace as regards future danger
likely to come to us from comets. There is little fear of the
destruction of humanity by these windy bags.

These ethereal beauties whose blond locks float carelessly upon the
azure night are not concerned with us; they seem to have no other
preoccupation than to race from sun to sun, visiting new Heavens,
indifferent to the astonishment they produce in us. They speed
restlessly and tirelessly through infinity; they are the Amazons of
space.

What suns, what worlds must they have visited since the moment of their
birth! If these splendid fugitives could relate the story of their
wanderings, how gladly should we listen to the enchanting descriptions
of the various abodes they have journeyed to! But alas! these mysterious
explorers are dumb; they tell none of their secrets, and we must needs
respect their enigmatic