Page:Popular Science Monthly Volume 38.djvu/355

This page has been validated.

Canis Majoris and the exceedingly beautiful star-curves in the neighborhood of Alpha Persei, both of which are figured in my Astronomy with an Opera-glass. No one can survey the heavens with any kind of an optical instrument for half an hour without discovering many similar instances. If it should ever be demonstrated that the individuals composing these star-rows have all an identical parallax, or, in other words, are all at the same distance from us, so much additional strength would be given to the argument that they owe their origin to a nebula which resembled in shape the figure that they mark out. But the inherent probability that the stars concerned in such cases really do have practically the same parallax is so great that actual measurement could hardly make it stronger.

Looking at the matter still more broadly, it is clear that the Milky Way itself may be regarded as the starry residuum of a far grander nebula even than that of Orion, which once completely encircled our heavens; while the origin of such stellar streams as we behold in Eridanus, Pisces, and other constellations having their stars comparatively widely separated and few in number, may be referred to smaller nebulous masses once scattered over the region of space included within and extending on each side of the plane of the galactic circle.

By Prof. T. H. HUXLEY.

THE rapid increase of natural knowledge, which is the chief characteristic of our age, is effected in various ways. The main army of science moves to the conquest of new worlds slowly and surely, nor ever cedes an inch of the territory gained. But the advance is covered and facilitated by the ceaseless activity of clouds of light troops provided with a weapon—always efficient, if not always an arm of precision—the scientific imagination. It is the business of these enfants perdus of science to make raids into the realm of ignorance wherever they see, or think they see, a chance; and cheerfully to accept defeat, or it may be annihilation, as the reward of error. Unfortunately, the public, which watches the progress of the campaign, too often mistakes a dashing incursion of the Uhlans for a forward movement of the main body; fondly imagining that the strategic movement to the rear, which occasionally follows, indicates a battle lost by science. And it must be confessed that the error is too often justified by the effects of the irrepressible tendency which men of science share with all other sorts of men known to me, to be impatient