"The higher harmonics and overtones of projected rad-energy are of a pitch sufficiently high to cause the atom to expand; by causing the atomoles to vibrate systematically the same influence will cause the atom to contract, and thus by changing the volume, Atomic pitch is varied." Keely, 1893
Commentary September, 2017
Varying the pitch of an atom is done by changing its volume. The volume is changed by excitation with "rad-energy" and its harmonics and/or overtones (taken to be substantially the same things). So what is rad-energy? See the link. Rad-energy is a frequency able to penetrate vacuum. We know today that radio waves can do this and all waves above radio frequencies. So he is talking what we call electromagnetic radiation for instance microwaves which we all know can boil water and cook food by exciting the molecules and atoms. Perhaps his description more closely resembles Ionizing Radiation, which it does when causing expansion OR contraction, either requiring its opposite polarization. When we examine the literature available to us we can see this type of action in Radiolysis, radioactivity, x-rays, Atomic Cluster X-Ray Emission, Water Radiolysis, etc. none of which were identified in Keely’s time hence his use of his own terms.