These weights have no other regard than the central line of the pole.

10 - m n a - 5 5. a feels the weight of the pole, which is 10. m feels the weight of the attached weights, which are also 10. n sustains 20 because it is found in the middle between the two tens, so that the pole will touch its support at n. The mover is always of greater power than the thing it moves.

n4 - m4. Here, although the suspended bodies are equidistant from the central line of the pole, the weights, though they are equal, appear each double the other; and this arises from the greater resistance that n has than m.

r f - k n o - a - g. That weight appears lighter which has greater resistance. Such power has a to go into g as f has to go into r; and thus f into o as a into h. a g cannot resist the weight a, because that weight rests entirely on the pole. Among heavy things, that one is the mover of the other which, by means of its natural descent, gives accidental motion to the other weight.

n h a. Here the act of friction is revealed.

Equal things do not overcome one another. That body has more resistant friction which is dragged along a more oblique line. Every mobile weighs along the line of its motion, and that one shows itself heavier which descends along a less oblique line. That body shows itself heavier which has weaker resistance. That part of the support resists less which is more remote from its fastening.