The book of Euclid on the heavy and the light and on the comparison of bodies to one another
1. Bodies are equal in size that fill equal places.
2. And which fill unequal places are said to be different in size.
3. And what are said to be great among bodies, are said to be ample among places.
4. Bodies are equal in force whose motions in equal times are through equal places in the same air or in the same water.
5. And those that traverse equal places in different times are said to be different in fortitude.
6. And what is the larger in force is the smaller in time.
7. Bodies are of the same kind of which in equals the force is equal.
8. If bodies equal in magnitude are different in force in respect to the same water or air, they are different in kind.
9. And the more solid [dense] is the stronger.
1. Of bodies that pass through unequal places in equal times, that which passes through the larger place is of larger force.
2. If of two bodies of the same kind one is the multiple of the other, then its force will be similarly in respect to the force of the other.
3. Of bodies of the same kind there is one proportion in size and power.
4. Bodies of which each is equipollent in kind to one, are of the same kind.
5. When there is one proportion in the size and force of bodies, they are of the same kind.