Levers and cords raising beams; reflex motion and balances

Which cord begins a beam's sliding motion

A cord is drawn in five positions to drag a beam, and Leonardo asks which of these cords first overcomes friction to set the beam moving. In a related note he states that once the beam's center of gravity reaches the central line of the angle on which it rests, the load vanishes for the mover raising it upright.

Three kinds of reflex (rebound) motion

For an object that strikes the ground and rebounds, Leonardo classes the reflex motions in three kinds. The first is longer than its incident motion, the second equal to it, and the third smaller.

Accidental weight to natural weight as real arm to potential arm

Leonardo sets the proportion: the accidental weight is to the natural weight as the real arm is to the potential arm. When a cord is fixed at one end of a level-lying rod and the angle between cord and beam is less than a right angle, the accidental-to-real weight ratio equals that of the counter-lever's length to its lever's.

Balance of a as 4 against b as 3

In the balance scheme a-c b, a can weigh as 4 against b's 3 with the addition of the accidental weight. That added element is power without weight, that is force, which does not press upon its fulcrum.

Rule of three and calculations

The left margin carries a worked table of numbers laid out as a rule-of-three calculation. Figures such as 7, 3, 5, 15 and 139 are arranged in the columns of the operation.

Note of expenses

A short household account lists abbreviated goods against money columns. Entries include items marked cr, sa, pes, pru and pani with their sums.

Dall'alto.

Corda in cinque posizioni, che trascina un trave:

Figure di travi che vengono rizzati:

Oggetto che batte sul suolo e rimbalza:

Tre figure di travi e asta sollevati da corde, la terza con:

Asta con:

Asta o trave sollevato da due corde, con:

Margine destro.

Schema di bilancia con:

Margine sinistro. Regola del tre, numeri e operazioni:

Nota di spese:

Corda applicata a un corpo triangolare con:

From above.

Cord in five positions, which drags a beam:

Figures of beams being raised upright:

Object that strikes the ground and rebounds:

Three beams and a rod raised by cords, the third with:

Rod with:

Rod or beam raised by two cords, with:

Right margin.

Balance scheme with:

Left margin. Rule of three, numbers and operations:

Note of expenses:

Cord applied to a triangular body, with: