Notebook on Mechanics and Natural Philosophy (1478-1518) - Page 11

⚠There is significant smudging and staining on the right-hand side of the middle section of the page, partially obscuring the second and third diagrams and the ends of some text lines. A small square paper patch has been applied over part of the damaged area.

of the old man, old age which does not feel its own harm at the end

A geometric diagram showing a weight 'm' suspended by a cord 'o-n-p' that passes through a system within a rectangular frame. Points are labeled with letters o, n, p, and m.

As much as weight m descends at p, so much will the force o rise at n; and the motion of weight m will be equal to that of weight n. That which descends is raised by the same amount, and this happens because the power original: "uirtù"; referring here to the physical capacity or potential of the force. of the motor original: "motore"; Leonardo uses this term for the source of motion or the acting force. extends through line o-n-p, which is of one and the same length, and such length does not vary by varying the position of that rope.

A diagram of a pulley-like system. Multiple lines descend from a horizontal bar, converging towards a central vertical line that terminates in a weight. Labels include a, b, c, d, m, n, p.

From the difference in the proportionality of the motor's motion, there will be a difference in the proportion of its power relative to its weight; and similarly, the difference in the proportionality of the weight compared to its heaviness original: "graueçça"; the inherent gravity or weight of the object. will result in a difference in the proportionality of the force of that motor.

A diagram showing a weight 'm' suspended from several ropes that fan out to different points on an arc above. Points are labeled with letters.

See, by the proportion of the motor's force to the weight moved, how much the motion of the motor will be compared to the motion of the weight moved. This will be verified by the line along which the motor moves compared with the line along which the weight moves, because weight m cannot descend except along line c-d, and the motor a-b cannot run except along the circular line a-b; it will not be pulled more by one rope than by the other.

A diagram of a horizontal beam 'a-g' from which many vertical ropes hang at equal intervals, all supporting a single weight 'm' below.

That rope will have greater force which is pulled by a motor of faster motion. Here it is proven by weight m, which, being suspended by the ropes a, b, c, d, e, f, g, h, i, l, has the same heaviness in each of these ropes, even though they are of various lengths, since the motor n moves along a line of equal length and at an equal velocity.