Remember to examine the weight of the wheel — that which it exerts upon the pole of resistance against its turning.

That first part of the wood which, by the blow of the cutting iron, is severed from the end of the wood will have a greater bounce than any other part driven off by the same blow.

The reason is that the part of the wood which first receives the percussion takes the blow upon itself at the first degree of its force, and therefore travels farther; the second part will leap less, because the fury of the blow has already fallen, and the third and the fourth less by degrees.

Water, air, and fire produce similar effects in their reboundings upon the objects that stand across their courses.

The wood which, by means of the blow of the cutting iron, is divided from the other wood will flee from it with the greater fury on one occasion than on another, according as the blow is more powerful on one occasion than on another, and the fleeing wood will travel the farther from that blow.

The reason for this is that, the blow being the most powerful and swift thing that a man can perform — as appears in the fourth proposition, where the nature of the blow is treated — the wood, which is joined together, once the edge of the iron (driven by the force of the man, by the motion of the descending hands, and by the weight and blow of the axe) has entered its surface, immediately the thickness of the axe follows the thin edge; and it comes with such vehemence and speed to widen and open the lips of that cut that it makes a supreme transverse force, so that the cut is opened as swiftly as it is deepened; whence, if it be entirely divided, it will flee from that blow with great speed, as is shown by experience.

The piece of wood separated from the other wood by the blow of the cutting iron will depart from the remaining wood at an angle equal to that of the inclination of the blow.

Everything of dense surface that falls upon a resistant object — the line of its rebound will be of the same obliquity as was the line of its incidence.

Water, or any other thing, that falls upon water causes the water that receives the blow to spread out beneath that blow and to encircle it; and once the cause of the blow is overcome, it passes above it in pyramidal form and then falls back to the common level.

The reason for this is that, when a drop of water falls from a roof upon other water, that part of the water which receives the blow cannot find room, nor flee within the other water with the speed at which it is assailed, because it would have to lift too great a weight upon itself in order to enter beneath so great a quantity of water; whence, having to obey by its own flight the driving of the thing that expels it from its place, and finding the neighbouring water — which does not receive the blow — not prepared for such flight, this first water cannot penetrate among it, and so it seeks the shortest way and runs among that which offers it least resistance, that is, the air. And that first circle which surrounds the struck place, closing again with fury (because it stood raised above the common surface of the water), reduces the water that fled upward into a pyramidal form. And if you should believe that the water which falls is the same that leaps up, let a little pebble fall upon the water and you will likewise see the water — and not the stone — leap up.