Can anyone deny that such credulity exists at the present day and elsewhere than in Russia? Are there not persons still who believe that the great comet of 1769, which appeared in the year that Napoleon was born, presaged the era of war which drenched in blood the end of the eighteenth century and the beginning of the nineteenth, and all the disasters which that too famous despot let loose on Europe and at last upon France herself? Have we not seen quite recently, in 1861, when the great comet of that year appeared, how it was currently reported in Italy, and doubtless elsewhere, that the new star was a sign of the speedy return of Francis II. and his restoration to the throne of the Two Sicilies; and also that it presaged the fall of the temporal power and the death of Pope Pius IX.?

We ought not to be astonished at the persistence of these superstitions, which only the spread of science can annihilate for ever. After seeing, in the following chapter, with what great difficulty true ideas on the subject of comets, suspected centuries ago, have achieved their final victory, we shall not be surprised to find that errors still remain in our own nineteenth century, in the midst of what we regard as enlightened populations, but which will never be truly enlightened until primary instruction shall have given to them more definite notions of physics, natural history, and astronomy.

CHAPTER II.

COMETARY ASTRONOMY UP TO THE TIME OF NEWTON.

SECTION I.

COMETS AND THE ASTRONOMERS OF EGYPT AND CHALDEA.

Had the Egyptians and Chaldeans any positive knowledge concerning comets?— Apollonius of Myndus; the Pythagoreans considered comets to be true stars— According to Aristotle they are transient meteors; fatal influence of the authority of this great philosopher upon the development of Cometary Astronomy.

SUCH is a very brief history of the errors into which the human mind we should rather say the human imaginationhas fallen with respect to comets. We have now to show how little by little, and by very slow degrees, truth disengaged itself from error, and to supplement the history of superstitions and prejudices by that of science. Both are instructive and throw light upon each other at all stages of their mutual development. Thus, for example, we may readily conceive that the irregular movements of comets, their sudden and unforeseen apparition, to say nothing of the singularity of their aspect, for a long time precluded the idea of their being true stars, subjected to fixed laws, like the planets. Centuries

of work, observation, and research were required for the discovery of the true system of the world as far as the sun, the planets, and the earth were concerned; but a difficulty of another kind stood in the way of the discovery of the true movements and nature of comets, since no trouble was taken to make exact and continuous observations of them. These difficulties, which were so great an impediment to science,

gave, on the contrary, singular encouragement to the prejudices, the superstitions, and the hypotheses which appear so ridiculous in our day. And, in addition, the predominance of mystic ideas contributed to deter astronomers from a study which fell rather within the province of the diviner than the

savant.

It is on this account all the more interesting to see a few just ideas, a few true conceptions, break through the dark night of ignorance and superstition. This happened, it is true, at a time and in countries where philosophy, not yet obscured by scholastic subtleties, was employed in explaining facts according to natural hypotheses; and where, by a bold and happy intuition, the Pythagorean school guessed without proving the true system of the world.

Are we to attribute to the Chaldeans and to the ancient Egyptians the first true conceptions concerning the nature of comets? That they regarded comets as stars subjected to regular movements, and not as simple meteors, we may believe, if it be true that they were in possession of means for predicting their return. Passages in Diodorus Siculus prove that the Chaldean and Egyptian astronomers hazarded such predictions; but, so far as our means enable us to judge, there is reason to suppose that these predictions were based upon particular beliefs, more astrological than astronomical. The passage which occurs in Diodorus Siculus relative to the Chaldeans is as follows:

'The Chaldeans,' says he, 'by a long series of observations have acquired a superior knowledge of the celestial bodies and their movements: a knowledge that enables them to announce future events in the lives of men; but according to them, five stars, which they call interpreters, and which others call planets, deserve particular consideration; their movement is of singular efficacy. They announce likewise the apparition of