When two bodies are brought near each other--the "nearness" being comparative, and, in some cases, meaning a distance of millions of miles--Heat is transmitted from the warmer to the cooler body, until the temperatures are equalized--that is until the two bodies vibrate in unison. In Physics we are taught that the "Transmission" of Heat may be accomplished in three ways, although the writer is of the opinion that the three ways are but three forms of one way. The first form is called "Conduction," whereby the vibration, or Heat, is conveyed along a body of Substance, from its warmer to its cooler parts--for instance, an iron poker with one end in the fire. The second form is called "Convection," whereby the visible motion of heated Substance, moving along the air--for instance, hot-air, hot-water, steam, etc., either by means of pipes, or by allowing them to pass freely through the air. The third form is called "Radiation," whereby the vibrations are believed to be transformed into "waves of the Ether," which will be spoken of later, in addition to what has been said on the subject in our chapter entitled "The Paradox of Science." The writer thinks that a little consideration will show us that the same rule operates in all of the above cases, and that "Conduction" and "Convection" are but forms of Radiation. For instance, in Conduction there must be a few Particles first set into vibration, the same gradually passing on to the others farther, and farther away. Passing _how_? "By contact," replies Physics. But, the Particles are never in absolute contact--there always is "plenty of space" between them. And so there must be some kind of "waves" passing through the space between them, which space is not filled with "air," or other form of Substance, but only with "the Ether," or _something that takes its place_. So that, after all, Conduction is but a form of Radiation. And the same rule will apply in the case of Convection.