Ragnarok : the age of fire and gravel

WHAT IS A COMET? 65

CHAPTER II. WHAT IS A COMET?

Iv the first place, are comets composed of solid, liquid, or gaseous substances? Are they something, or the next thing to nothing ?

Tt has been supposed by some that they are made of the most attenuated gases, so imponderable that if the earth were to pass through one of them we would be unconscious of the contact. Others have imagined them to be mere smoke+yreaths, faint mists, so rarefied that the substance of one a hundred million miles long could, like the genie in the Arabian story, be inclosed in one of Solomon’s brass bottles.

But the results of recent researches contradict these views :

Padre Secchi, of Rome, observed, in Donati’s comet, of 1858, from the 15th to the 22d of October, that the nucleus threw out intermittingly from itself appendages having the form of brilliant, coma-shaped masses of incandescent substance twisted violently backward. He accounts for these very remarkable changes of configuration by the influence first of the sun’s heat upon the comet’s substance as it approached toward perihelion, and afterward by the production in the luminous emanations thus generated of enormous tides and perturbation deraagements. Some of the most conspicuous of these luminous developments occurred on October 11th, when the comet Mi at its nearest approach to the earth, and on