Astronomical Myths: Based on Flammarions's "History of the Heavens"

by J. F. Blake; Camille Flammarion

Fig. 56.—An Egg Marked with a Comet.

The last blow to the superstitious fear of the comets was given by Halley, when he proved that they circulated like planets round the sun, and that the comets noticed in 837, 1066, 1378, 1456, 1531, 1607, 1682 were all one, whose period was about 76 years, and which would return in 1759, which prediction was verified, and the comet went afterwards by the name of this astronomer. It returned again in 1835, and will revisit us in 1911.

Even after the fear arising from the relics of astrology had died away, another totally different alarm was connected with comets—an alarm which has not entirely subsided even in our own times. This is that a comet may come in contact with the earth and destroy it by the collision. The most remarkable panic in this respect was that which arose in Paris in 1773. At the previous meeting of the Academy of Sciences, M. Lalande was to have read an interesting paper, but the time failed. It was on the subject of comets that could, by approaching the earth, cause its destruction, with special reference to the one that was soon to come. From the title only of the paper the most dreadful fears were spread abroad, and, increasing day by day, were with great difficulty allayed. The house of M. Lalande was filled with those who came to question him on the memoir in question. The fermentation was so great that some devout people, as ignorant as weak, asked the archbishop to make a forty hours' prayer to turn away the enormous deluge that they feared, and the prelate was nearly going to order these prayers, if the members of the Academy had not persuaded him how ridiculous it would be. Finally, M. Lalande, finding it impossible to answer all the questions put to him about his fatal memoir, and wishing to prevent the real evils that might arise from the frightened imaginations of the weak, caused it to be printed, and made it as clear as was possible. When it appeared, it was found that he stated that of the sixty comets known there were eight which could, by coming too near the earth, say within 40,000 miles, occasion such a pressure that the sea would leave its bed and cover part of the globe, but that in any case this could not happen till after twenty years. This was too long to make it worth while to make provision for it, and the effervescence subsided.

A similar case to this occurred with respect to Biela's comet, which was to return in 1832. In calculating its reappearance in this year, Damoiseau found that it would pass through the plane of the earth's orbit on the 29th of October. Rushing away with this, the papers made out that a collision was inevitable, and the end of the world was come. But no one thought to inquire where the earth would be when the comet passed through the plane in which it revolved. Arago, however, set people's minds at rest by pointing out that at that time the earth would be a month's journey from the spot, which with the rate at which the earth is moving would correspond to a distance of sixty millions of miles.

This, like other frights, passed away, but was repeated again in 1840 and 1857 with like results, and even in 1872 a similar end to the world was announced to the public for the 12th of August, on the supposed authority of a Professor at Geneva, but who had never said what was supposed.

But in reality all cause of fear has now passed away, since it has been proved that the comet is made of gaseous matter in a state of extreme tenuity, so that, though it may make great show in the heavens, the whole mass may not weigh more than a few pounds; and we have in addition the testimony of experience, which might have been relied on on the occasions above referred to, for in 1770 Lexele's comet was seen to pass through the satellites of Jupiter without deranging them in the least, but was itself thrown entirely out of its path, while there is reason to believe that on the 29th of June, 1861, the earth remained several hours in the tail of a comet without having experienced the slightest inconvenience.

As to the nature of comets, the opinions that have been held have been mostly very vague. Metrodorus thought they were reflections from the sun; Democritus, a concourse of several stars; Aristotle, a collection of exhalations which had become dry and inflamed; Strabo, that they are the splendour of a star enveloped in a cloud; Heracletes of Pontus, an elevated cloud which gave out much light; Epigenes, some terrestrial matter that had caught fire, and was agitated by the wind; Bœcius, part of the air, coloured; Anaxagoras, sparks fallen from the elementary fire; Xenophanes, a motion and spreading out of clouds which caught fire; and Descartes, the débris of vortices that had been destroyed, the fragments of which were coming towards us.

It is said that the Chaldæans held the opinion that they were analogous to planets by their regular course, and that when we ceased to see them, it was because they had gone too far from us; and Seneca followed this explanation, since he regarded them as globes turning in the heavens, and which appear and disappear in certain times, and whose periodical motions might be known by regular observation.

We have thus traced the particular ideas that have attached themselves to eclipses and comets, as the two most remarkable of the extraordinary phenomena of the heavens, and have seen how the fears and superstitions of mankind have been inevitably linked with them in the earlier days of ignorance and darkness, but they are only part of a system of phenomena, and have been no more connected with superstition than others less remarkable, except in proportion to their remarkableness. Other minor appearances that are at all unusual have, on the same belief in the inextricable union of celestial and terrestrial matters, been made the signs of calamities or extra-prosperity; the doleful side of human nature being usually the strongest, the former have been chosen more often than the latter.