Chapter 6

Josiah Wedgwood and the clay pyrometer--Count Rumford and the vibratory theory of heat--His experiments with boring cannon to determine the nature of heat--Causing water to boil by the friction of the borer--His final determination that heat is a form of motion--Thomas Young and the wave theory of light--His paper on the theory of light and colors--His exposition of the colors of thin plates--Of the colors of thick plates, and of striated surfaces,--Arago and Fresnel champion the wave theory--opposition to the theory by Biot--The French Academy's tacit acceptance of the correctness of the theory by its admission of Fresnel as a member.