Key points are not available for this paper at this time.
Abstract When a surface is a full radiator and absorber its temperature can be determined at once by the fourth-power law if we know the rate at which it is radiating energy. If it is radiating what it receives from the sun, then a knowledge of the solar constant enables us to find the temperature. We can thus make estimates of the highest temperature which a surface can reach when it is only receiving heat from the sun. We can also make more or less approximate estimates of the temperatures of the planetary surfaces by assuming conditions under which the radiation takes place, and we can determine, fairly exactly, the temperatures of very small bodies in interplanetary space. These determinations require a knowledge of the constant of radiation and of either the solar constant or the effective temperature of the sun, either of which, as is well known, can be found from the other by means of the radiation constant. It will be convenient to give here the values of these quantities before proceeding to apply them to our special problems.
John Henry Poynting (Fri,) studied this question.