“Yes, bands of vapour,” corrected Alan.
“Well—vapour. These bands completely encircle our world. They are saturated with a composition of gas, sulphuric ether I think you would call it. Well, this gas acts as a trap to the sun’s rays. It admits the solar rays to our planet but prevents their withdrawal. Therefore it permits the heat to enter, but prevents its escape.”
“Well?”
“Consequently we get the maximum of light, and an equable temperature.”
“Do you then, have no seasons here?”
“Seasons?”
“Yes, Spring or Winter.”
“Oh yes, it is cold at the poles—very cold, but as we get nearer to the equator it becomes warmer, and hardly varies. You see, my Alan, our world differs from yours. The axis of rotation is almost perpendicular to our orbit, consequently we are not subject to seasons as you were in Quilphis.”
“I didn’t know that before.”
“We too, are more flattened at each end—indeed, there are many differences between our world that is, and yours that was.”