George Forbes

“ When a body is heated, and the vortex atoms are rushing about, their mutual collisions originate vibrations in themselves which, when they are free, have a definite period, or periods, depending upon the nature of each vortex atom. ”

“ Similarly, all bodies are driven towards each other with a force varying as the product of the masses. Sir William Thomson supposes ultramundane corpuscles to be vortex rings with no hole in the centre and elongated, like a serpent rushing forwards and always turning inside out, spitting its inwards out at its mouth, and absorbing its skin at the other end. Collisions with vortex atoms would not result in a destruction of velocity and consequent enormous generation of heat, but energy of translation is converted into some other form of energy, perhaps energy of vibration. ”

“ The others pass right through the earth. Owing to these collisions, however, a smaller number of ultramundane corpuscles are to be found moving in the direction from the earth than towards it. Thus the earth acts as a shield, Protecting surrounding bodies from the shower of ultramundane corpuscles in that direction. Hence the moon, and bodies on the earth's surface, are battered by ultramundane corpuscles most in the direction towards the earth. This force, driving bodies towards the earth, explains terrestrial gravitation. ”