The world machine : the first phase the cosmic mechanism / by Carl Snyder.

  • Snyder, Carl, 1869-1946.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The world machine : the first phase the cosmic mechanism / by Carl Snyder. Source: Wellcome Collection.

    340/510 (page 322)
    to the solid test. Mapping, plotting, comparing the bizarre and bewildering movements of translation, which with his great reflector he can demonstrate to exist, Herschel comes at last to perceive or imagine that in one direction of the heavens the stars are slowly separating, while in the opposite direction they are surely coming together. You watch a herd of sheep upon a hillside, or a multitude of men at a distance ; they form a kind of blot or blur. A little nearer you begin to distinguish their heads ; finally you perceive that they may be all standing or moving about at some distance apart. As you draw away, the process of separation is reversed—the single units again become a blur. There was hardly any mistaking the meaning of Herschel’s observation. It was that we are drawing nearer to the stars in one direction, flying farther and farther from them in another. The differences were almost inscrutably minute ; the detection of each single motion had been in itself a long and painful task. Moreover, the number of firmly established proper motions which he had to go on was very small. In his first paper on the subject he can use only fourteen. He did not reach his conclusion from the mere weight of his evidence ; the evidence was slight. You review the prodigious industry of Herschel, and you gain the impression that he may have been one of those tireless and unflagging investigators who lay bare the truth simply by grubbing. Before his journals were published a great many people thought this of Darwin. We forget that the number of grubbers is not small. That Herschel’s deter- mination of the direction of solar motion was something more is evident from the fact that it was entirely distrusted by almost all the astronomers of his generation. Curiously enough, only a few months after his results were published, a French observer, Prevost, reached a similar de- duction from another series of observations than those which Herschel had employed. Their results were in quite striking agreement; they pointed to the idea that our system is moving, rather slowly as cosmic motions go, towards the constellation of Hercules. This point may readily be fixed by extending a line drawn through the three stars in the handle of the Dipper which lie in a straight line, to a distance about twice the extreme length of the Dipper itself, that is to say, to a point about equally distant from the Pole-star and from Arcturus.