The Nature of Comets

Some say that the tail does not belong to the comet itself, but is occasionally assumed by it on its course in certain situations. These views involve impossibilities, some of which are common to all of them, while others are peculiar to some only. But as a matter of fact no planet has been observed besides the five, and all of them are often visible above the horizon together at the same time. More comets than one have often appeared simultaneously.