Of tackles and ropes.

Here follows what is missing opposite, in the margin at the foot.

d a - e c b - 3 4

Therefore we shall say that the penultimate rope can do more than the last rope and less than the antepenultimate, and the antepenultimate can do less than the first; and from this it follows that the load placed on the last rope is much less able to resist the mover placed on the first rope than that mover is able to move the load set on the last rope.

First — One of the ropes of the tackle feels the more weight the faster it is. It follows that the slower rope feels less weight.

Second — By the foregoing it is proved that the side of the tackle rises more which is moved by the faster rope. Therefore that side rises less which is moved by the slower rope of the tackle.

Where the rope of the tackle will break.

Third — The rope that moves in the tackle, being of itself of uniform strength, will always break at the start where the mover's rope meets the first pulley. This is proved by the first proposition, which says that "the faster rope feels more weight." Therefore, the mover's rope being the fastest, it feels more weight, and by the concept: "That rope breaks soonest which feels the most weight." And this is part of our purpose. It remains for us to say that "that part of the rope breaks soonest which is nearest to its upper support."