Motion of falling bodies, friction, and percussion

Simple and composite motion of a spherical heavy body

Leonardo names two motions a spherical heavy body can make through the air: simple, in which the surface moves as much as the centre, and composite, in which the surface is faster than the centre. He notes the composite (rotary) impetus is poorly maintained and always diminishes, and that over long travel composite motion in the air reverts to simple.

The curving descent of a rising heavy body (b, c, a)

A body that rises weighs along the line of motion, but as its path bends it weighs toward the earth; the impetus draws it from the mover while the growing weight brings it earthward. By this division of powers the trajectory curves until the impetus is destroyed and the weight, restored to full integrity, gives new impetus toward the centre of the world.

Friction, weight and obliquity of weights on cords (a, b, c)

Three weights a, b and c drawn within a circle show how friction trades off against the weight borne by the cord. a stands at maximum friction and gives no weight to its cord; c gives maximum weight and its friction dies; b, at middle obliquity, has half c's weight and half a's friction. As friction grows with changing obliquity, the weight lessens.

Friction equals a quarter of the rubbed weight

A rule repeated across the sheet holds that the power of flat friction is a quarter of the weight of the thing rubbed. It recurs beside figures of horizontally, obliquely and vertically arranged weights, and again for a cylinder resting in a hollow, labelled 'curved friction'.

Geometric figures at the upper right

A dense cluster of small squares, rectangles and circles at the upper right carries inscribed diagonals and curves, together with an angle or semicircle diagram. They accompany the mechanical text but are not transcribed in the bundle.

Architectural sketches in the lower right corner

In the lower right corner are small architectural drawings, annotated 'balls' and with the name Giovannino. They sit apart from the physics of motion that fills the rest of the sheet.

In alto, a destra.

Foglio capovolto. A sinistra.

Linea curva ascendente e discendente, con:

Colonna centrale

Dal margine destro.

Due sfere con:

Angolo inferiore destro, disegni architettonici, con:

Sfera, con:

Entro un cerchio tre pesi tirati da corde, con:

Figura di tre pesi: orizzontale, obliquo, verticale:

Figura di sezione di cilindro adagiato in un incavo e congiunto a corda e carrucola, con:

Numeri, a destra:

Upper right.

Sheet turned upside down. At left.

Ascending and descending curved line, with:

Central column.

From the right margin.

Two spheres, with:

Lower right corner, architectural drawings, with:

Sphere, with:

Within a circle, three weights pulled by cords, with:

Figure of three weights: horizontal, oblique, vertical.

Section of a cylinder set in a hollow, joined to a cord and pulley, with:

Numbers, at right: