584 KANSAS CITY REVIEW OF SCIENCE. 



gathering in of meteoric bodies, for in reality this process belongs to the contrac- 

 tion theory; it has, however, been abundantly demonstrated that the actual 

 amount of sun heat which could be derived from the drawing in of matter now 

 outside the solar globe can be but very small. We are left, in fine, no recourse — 

 so far as our present knowledge extends— but to regard the process of contraction 

 taking place within the solar globe as the true source of all or very nearly all the 

 heat and light which the sun emits, and therefore of every form of force and life 

 on this earth and on whatever other members of the solar system may be the 

 abode of life or a scene of the display of any forms of force not derived from 

 internal heat and energy. 



But now at the very outset, what a mighty mystery is thus unveiled ! It 

 seemed wonderful enough to recognize in what we fondly call inert matter the 

 source of the energies which guide the heavenly bodies in their motions. I know 

 indeed nothing more mysterious (more hopelessly mysterious, one might say, if 

 one could limit the possibilities of future research) than the mystery of gravity. It 

 has been said, and truly said, that 



Nature and Nature's laws lay hid in night, 

 God said, " Let Newton be," and all was light. 



All was indeed light where before men had been groping in darkness. But 

 outside the region where they had thus been searching, far vaster regions of dark- 

 ness were revealed. A veil was lifted and one of nature's mysteries was interpre- 

 ted, but a more impenetrable veil was seen beyond, which as yet no man has 

 even hoped to lift. What greater mystery can there be than this, that matter 

 acts where it is not? The sun on the earth and all his planets, the earth on the 

 moon, Jupiter and Saturn on their world systems, planet on planet, star on star, 

 nay, every particle of matter on every other throughout infinity of space. And 

 not only so, but time apparently annihilated as well as distance. For it has been 

 shown that unless the force of gravity traversed distance with far greater velocity, 

 nay, with many times the velocity of light (187,000 miles per second), the whole 

 mechanism of the solar system would long since have gone wrong. Nor has it 

 yet been shown how minute the time intervals are in which practical infinities of 

 distance are traversed by this all-pervading attractive action. 



And now we find that not only is " inert" matter thus intensely, one may 

 say infinitely, energetic, as a cause of motion, but that it is the real source of the 

 light and heat, which are in effect the very life of the universe itself. Within our 

 •own earth, the movements we call earthquakes, as well as all such disturbances as 

 volcanic eruptions, geysers, and so forth, are all primarily due to the process of 

 steady contraction taking place under the action of terrestrial gravity, though of 

 course the proximate cause of each such disturbance is the heat generated during 

 the process of contraction. In each planet, no doubt, similar processes are taking 

 place, with greater or less energy according as a planet is younger or older. And 

 now we see the mighty mass of the sun, steadily by its gravitating energy gene- 

 rating heat, whose emission is in fact the very life of the solar system. In other 



