Thomas Proctor Hall

“ Michelson and Morley have shown that the ether close to and in the earth moves with the earth, which indicates that the ether does not move among atoms without some resistance corresponding to friction. The existence of an ether strain such as that in a leyden jar also shows that there is a resistance on the part of the ether to the kind of motion that takes place in the electric discharge. Ether has mass, since it conveys energy by waves which have a finite velocity. ”

“ A feasible plan is to surround a delicately poised mass by a thick pair of hemispheres (which may be hollow for liquids) , and note with a refractometer any change of position, which, since the attraction of a sphere at a point within it is zero, will be due either to induction or to irregularities of the sphere. Errors due to irregularities may be readily eliminated by rotating the sphere. ”

“ It does not necessarily follow that the law holds with absolute accuracy, or that it holds at all for distances comparable with atomic dimensions. All that we can say is that for distances moderate and great the law expresses the facts as accurately as they have been experimentally determined. ”

“ The field of force about an atom is also capable of representation by a function of the space co-ordinates such that when the distance r from the atom is relatively great the equipotential surfaces are very nearly spheres. ”

“ The strain in each case extends to infinity, or as far as the ether extends. If the displacement of ether were prevented from extending on one side by a rigid imaginary wall, the whole strain on that side would take place between the atom and the wall, and would be more intense than on the opposite side. ”

“ The ether in like manner yields easily before [49] moving bodies whose velocity is relatively small, not exceeding a few hundred kilometers per second, but acts as a solid toward such high velocities as that of light, which is nearly 300,000 kilometers per second. Copper, again, is a familiar example of a metal having nearly perfect elasticity within a certain limit of strain. Beyond that limit it yields to pressure like a fluid. The ether shows the same combination of properties with a wider limit of strain. Ether in a vacuum will bear a very great electrical strain without yielding ”