789. What is the specific gravity of a body?
It is its weight estimated relatively to the weights of other bodies.
790. What determines the force with which bodies fall to the earth?
Generally speaking, their specific gravity, which is proportionate to the density, or compactness of the atoms of which they are composed.
791. Why does a feather fall to the earth more gradually than a shilling?
Because the specific gravity of the feather and of the shilling is relative to that of the air, the medium through which the feather and the shilling pass. If there were no air, a shilling and a feather dropped at the same time from a height of forty miles, would reach the earth at the same moment.
CHAPTER XXXVII.
"Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding."