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.