The thick axle-pins of cart wheels heat up much more than thin pins, because in one and the same turn of the wheel a mark made on the thick pin will be rubbed by one arm's length of its socket, whereas on the thin pin only by 1/8.

There are three qualities of the arms of balances, namely equal, unequal-natural, and unequal-positive.

Keep these for last, and they will be good for the section on the tackles.

Here there are no unequal-positive arms.

All the positions of the cords can be varied, here in the circular ones as in the straight ones, because they are alike in nature.

There are three variations of the fulcrum-pins, namely on the beam of the balance: above, or below.

There are two supports of the pins, namely with the pendant and without.

Without a pin the equalization of the weights and the friction is made.

20 pounds of azure of Germany, one ducat — the pound: 80 lire, s. , d.

60 pounds of white lead, s. 60 the pound: 15 lire, s. , d.

1 1/2 pounds, L 4 the pound: 6 lire, s. , d.

Vermilion, 2 pounds, at s. 18 the pound: 1 lira, 16 s., d.

Green, 6 pounds, s. 12 the pound: 3 lire, 12 s., d.

Yellow, 4 pounds, at s. 12 the pound: 2 lire, 8 s., d.

Red lead, 1 pound, at s. 8 the pound: 0 lire, 8 s., d.

Aiorica, 4 pounds, s. 2 the pound: 0 lire, 8 s., d.

Ochre, six pounds, at 1 the pound: 0 lire, 6 s., d.

Mineral black, s. 2 the pound, for 20: 2 lire, 0 s., d.

Wax for making the stars, 25 pounds at s. the pound: lire, s., d.

Oil for painting, 40 pounds, 5 soldi the pound: 10 lire, s., d.

In sum 120 lire and 18 s., without the gold, and the tin for applying the gold: 120 lire, 18 s., d.

Here, in motion, the nature of the balance changes, that is, from equal arms they become unequal.

Here the same is done as above.

When two things move in one and the same direction, of which one is faster than the other, the slower will appear to move in a motion contrary to that of the faster, there being no other comparison with something motionless. And this is seen in the clouds, which move like the sun or moon toward the west, or like boats on the high sea against the horizon of air and water.