Page:Popular Science Monthly Volume 2.djvu/670

670 Gentlemen, I have restricted my remarks to a few divisions of the general subject of the importance of the cultivation of science, and leave it to others to develop other points of the same subject in their bearing on the welfare of man.



HE speculative views of Lambert and Kant led them to the adoption of a Nebular Hypothesis, and to the idea of a perpetual development in the regions of space. Sir William Herschel, after long hesitation, was ultimately led, by the surer path of observation and cautious induction, to the adoption of similar views, in relation to the existence of a self-luminous substance of a highly-attenuated nature, distributed through the celestial realms. At a later period, in 1811, he communicated to the Royal Society an exposition of his famous hypothesis of the transformation of nebulae into stars.

Sir William Herschel made no attempt to extend his hypothesis to a cosmogony of our solar system. If, therefore, the "Nebular Hypothesis" is restricted to the theory which professes to explain the genesis of our solar system, it is only analogically related to the loftier speculations of Sir William Herschel, in regard to the processes of star-formation going on in the stellar realms. In this restricted sense, the "Nebular Hypothesis" is due to Laplace. This illustrious mathematician, with a modesty and diffidence befitting a true philosopher, endeavored to lay rational foundations for a cosmogony of the solar system. This sublime speculation has been egregiously misunderstood and misrepresented alike in itself and in its tendencies.

The lecturer proposed to disconnect Laplace's Nebular Hypothesis from the question of the general diffusion of cosmical vapor in the celestial regions. Indeed, the origin of Laplace's hypothesis did not lie in Herschel's speculations in relation to the transformation of nebula? into stars and clusters of stars. In contemplating our solar system, he discerned numerous harmonies and adjustments, which were not accounted for by the law of gravitation, which induced him to infer that all its members were of one family of a common origin. The Nebular Hypothesis was framed to explain and coordinate these facts, and, if possible, to refer them to established mechanical principles. Under this view, the lecturer considered the Nebular Hypothesis in two aspects—viz.: As a pure hypothesis, framed to explain the arrangements of the solar system; and as a physical reality, indicating the actual process by which the phenomena were evolved or produced.