Heronis Alexandrini spiritalium liber

when this has been cooled according to the movement of the sun, they are carried down again into a lower place. But winds arise from a vehement exhalation of air, both expelled and thinned; and they are always moving the air which is next in line. The motion of the air, however, is not equally fast according to every place, but it is indeed more vehement near the exhalation, but weaker when it is far from that place in which it is moved, just as it happens in heavy things which are carried upward. For these are moved more quickly near the place close to the bottom, in which there is also the driving force; but more slowly in the upper place, with the force that drove them no longer following as strongly, they are carried back again to their natural place, namely the lower one. For if the force itself had driven them with equal speed, it would surely never have ceased. But now, with it ceasing little by little, and as if consumed, the velocity of the movement also ceases. Water also is changed into an earthy substance; for when we pour water into some earthy and concave place, a little later the water, having been imbibed by the earthy substance...