Quotation from: The Notebooks of Leonardo Da Vinci

Written by: Leonardo da Vinci

The element of fire acts upon a wave of air in the same way as the
air does on water, or as water does on a mass of sand --that is
earth; and their motions are in the same proportions as those of the
motors acting upon them.

998.

OF MOTION.

I ask whether the true motion of the clouds can be known by the
motion of their shadows; and in like manner of the motion of the
sun.