Jules Verne

“ In the case of the earth coming into contact with a comet destitute of a nucleus, there would be no violent collision; strictly speaking, there would be no shock at all. The astronomer Faye asserts that a cannon ball would find more resistance in a cobweb than in the nebulous parts of a comet; and for the nebulous matter to be injurious, it must either be incandescent, in which case it would scorch up the surface of the earth, or it must be impregnated with noxious elements, in which case it might be fatally destructive to life. ”

“ Uncomfortable as was their temporary abode, Servadac and his attendant made no complaints: neither of them was dainty in the matter either of board or lodging.
“Give a man a little philosophy and a good digestion, and he will thrive anywhere,” was a favourite speech of the captain's. A true Gascon, he had his philosophy, like his pocket-money, always at hand; and as for his digestion, it may be doubted whether the weight of all the waters of the Garonne would have caused it any inconvenience. And in this respect Ben Zoof was quite a match for his matter ”

“ It is a property that must make their external form very susceptible of change, and tends in a degree to make them difficult of recognition. The same transparency characterises the tail, the development of which is apparently due entirely to the evaporation of the coma under the action of solar heat; in proof of which it is notified that no tail, either single or multiple, has ever been found attached to a comet until that comet has arrived within 80,000,000 miles of the sun; whilst it has been observed that some comets, presumably composed of denser structure, have emitted no tail at all. ”

“ Fourthly, then, Professor Rosette had to discuss the remaining question to bring his treatise to a close; as to the probable consequences of such a collision.
These consequences would manifestly vary according as the comet had or had not a nucleus. As some fruits have no kernel, so some comets have no nucleus, and such is the tenuity of their substance, that stars of the tenth magnitude have been seen through them without any sensible diminution of light. ”

“ This latter contingency, however, is unlikely to arise; for, according to Babinet, the earth's atmosphere possesses sufficient density of its own to resist the penetration of any cometary vapours, of which the tenuity is so slight, that Newton has calculated that if a comet, without a nucleus, 1,000,000,000 miles in radius, were reduced to the density of the air at the earth's surface, it might all be contained in a thimble less than an inch in diameter. ”

“ First of all, however, rises the preliminary question whether in any case the nucleus of a comet is really solid, There can be no doubt that if a comet can attain a degree of concentration sufficient to pass out of its gaseous condition, it will, if interposed between the earth and a star, make an occupation of that star. ”

“ The truth seems to be that their number really sets all calculation at defiance; so erratic, moreover, are their movements, that they sometimes pass from system to system, and whilst some, entirely escaping the influence of the sun, vanish, to find a new centre of attraction, others never before observed make their appearance upon the terrestrial horizon. ”

“ Even the comets which belong exclusively to our own system are by no means exempt from strange irregularities; the orbits of several, ceasing to be ellipses, have become parabolas or hyperbolas; and the planets, Jupiter in particular, have been observed to exercise a large disturbing action upon their paths.
Secondly: under the head of periodic and non-periodic comets, Professor Rosette had stated that as many as 500 or 600 comets have been made objects of careful astronomical investigation ”

“ Concluding thus that from comets purely nebulous there was a minimum of danger to be apprehended, the professor proceeded to inquire what would be the result of concussion if the comet consisted of a solid nucleus. ”

“ Gambart's comet (otherwise known as Biela's) was noticed in 1772, 1789, 1795, and 1805; but it was not until the 28th of February, 1826, that its elements were satisfactorily determined. Its motion is direct, and its period of revolution 2410 days, or about seven years. At perihelion it passes 82,000,000 miles from the sun, rather nearer than the earth; at aphelion it is beyond the orbit of Jupiter. ”

“ The gourbi was stocked with a month's provisions, water in abundance could be obtained from an adjacent cistern, and a little foraging was sufficient to supply the requirements of the stable, whilst all other necessities could be satisfied by the marvellous fertility of the plain between Tenes and Mostaganem, which fairly rivalled the rich country of the Mitidja. ”

“ In truth, his character of staff-officer was now entirely absorbed into that of the Gascon poet. Whether he imagined that the compasses would bestow upon his verses the measure of a mathematical accuracy, or whether he fancied that the parti-coloured lines would lend variety to his rhythm, it is impossible to determine ”