And whither will it tend?
It will tend to the centre of the earth.
And why not along other lines?
Because the weight which meets with no resistance will descend by the shortest way to the lowest depth, and the lowest depth is the centre of the earth.
And how does a weight find the centre of the earth with such directness?
Because it does not proceed at random, wandering by diverse courses.
Phenomena governed by Mechanical Laws
83.
Instrumental science, that is to say, mechanics, is the most noble and most useful of sciences, inasmuch as by means of it all living bodies which have movement act; and this movement has its origin in the centre of gravity which is placed in the middle, dividing unequal weights, and it has dearth and wealth of muscles and lever also and counter-lever.
84.