Weight, pulleys and proportional motion (1 August 1499)

Dated heading: of motion and weight

On the first day of August 1499 Leonardo notes that he wrote here of motion and weight.

Weight on a cord over a single pulley

A weight on one side of a cord over a single pulley can be overcome by a smaller weight on the other side, yet the motions are never equal — one motion is to the other as, conversely, one weight is to the other. The circle n b d always represents the true length of the cord n m, and the excess beyond it is the cord lost on the side m S.

The case of the sliding cord

Where the perpendicular cord slides, one must take the whole cord n m o, because all that length is lost on the side t x, and by just so much the weight x has risen.

A doubled reckoning with two weights

Here the reckoning is doubled: the weight S, moving through r a, raises the two opposite weights equally — to K the motion a n and to h the motion c a — so it lifts twice as much weight through less than half the distance the weight m did above.

Screw with an anti-turning spring

A spring a is placed so that the male of the screw does not turn together with its female — the nut.

Devices for Duchess Isabella's bath

Beside four mechanical drawings Leonardo records that they were made for the stove, or bath, of Duchess Isabella.

Figura colle lettere:

Sopra la figura colle lettere:

Figura colle lettere:

Figura colle lettere:

In basso, accanto a quattro disegni meccanici:

Figura con:

Figura con:

Figure with the letters:

Above the figure with the letters:

Figure with the letters:

Figure with the letters:

Below, beside four mechanical drawings:

Figure with:

Figure with:

Weight, pulleys and proportional motion (1 August 1499)

On this page

Dated heading: of motion and weight

Weight on a cord over a single pulley

The case of the sliding cord

A doubled reckoning with two weights

Screw with an anti-turning spring

Devices for Duchess Isabella's bath