"Look here, I have succeeded at last in fetching some gold from the sun."

"Heat rays have the same nature as light rays... The invisible heat rays are distinguished from light rays only by the…"

"All heat rays follow the same laws in their propagation, which are known for light rays."

"Of the heat rays... sent... to a body by its surroundings a part are absorbed, the others are... varied by reflection…"

"Through the radiations... a body sends out, the quantity of ... it contains will... sustain a loss... equivalent to t…"

"[I]n certain cases an exception to this rule may occur... [when] absorption and the radiation produce other changes i…"

"Such cases should be excluded on the assumption that neither by means of the rays which it radiates or absorbs, nor b…"

"Let a body which satisfies these conditions be surrounded by an enclosure, having the same temperature [and kept cons…"

"A '... must have the same as the medium... then there will be no reflection at its surface, and all incident rays... …"

"This investigation will be... simplified if we imagine the enclosure... composed... of bodies which, for infinitely s…"