We conclude... that there exists a physical cause always present which modifies the temperature at the surface of the earth, and gives this planet a … - Joseph Fourier

We shall now consider that peculiar heat which our globe had at the time of the formation of the planets, and which continues to be dissipated at the surface under the influence of the low temperature of the planetary space.

The heat of the earth is derived from three sources...
1. ...[S]olar rays; the unequal distribution of which causes diversities of climate.
2. ...[T]he common temperature of the planetary spaces; being exposed to the radiation from the innumerable stars which surround the solar system.
3. The earth preserves in its interior that primitive heat which it had at the time of the first formation of the planets. ...We will show ...the principle features of these phenomena.

[I]f all the strata of air of... the atmosphere... preserved their density with their transparency, and lost only the mobility... peculiar to them, this mass of air, thus become solid, on being exposed to the rays of the sun, would produce an effect the same in kind... [as] just described.