On the blast.

The thunder of a bombard pointed at the water will kill all the animals found in the water.

On noise.

If you take a small cask or another resonant vessel and cover it with wetted vellum, and once it has dried, thread a small waxed cord in this way

and pull it using a glove waxed with a bit of pitch, you will hear a strange sound.

l – d c (d)  a b – p S r – m n

[II]

On weights.

Equal weights moved equal distances from the center, or pivot, of the balance will keep the ends of the balance equidistant from the support of the balance.  That is, if weights m and n are attached at c and a and are of equal weight and equal distance from the pivot, S, of the balance, and you shift them away from this pivot, to d and to b, and these distances are equal, then the ends of the balance, p and r, will remain at an equal distance from l.

a  b o  c d – 1  3

[III]

On weights.

When unequal weights are positioned at unequal distances on the balance so that it rests flat, and then moved apart by equal distances, the balance will tip toward the part having the greater weight.

That is, if weight b weighs one pound, it will be counterweighted by three pounds at c.  The reason is that, if b is three inches away from the pivot and c is one inch away, it is necessary to restore it so that each part on either side of the pivot is of equal numbers.  That is, if c is four, that is, three pounds of weight and one of space, which make four, similarly, b will be three spaces and one pound, which make four.  Therefore, since there are four on each side, considering the pounds and the spaces together, the balance stays level.

Now, if you want to move the two weights[1] by the same distance from their locations, the greater weight will draw the arm of the balance downward.  And the reason is that if you pull b toward a and, similarly, c toward d, the distances from the pivot to the weights depart from their previous proportion.  This is because c o entered three times into o b previously, and when you move the weights to a and to d, then d o enters into o a only two times, and not three times, as before.  In order to equalize the balance again, it would be necessary for the weight of three to become two, and then that would stand well.  Otherwise, the three would go down.

On weight.

If two men carry a beam up a stairway and the piece of wood is of equal width and weight, the one below bearing the wood will feel exactly as much as the one bearing above.  And if the whole piece of wood tends to fall toward the center [of the earth], all of its parts will be of the same desire, and since they want to fall straight down, they will produce the above-mentioned effect.

a n - m - x

[IV]

It is impossible for a rope burdened with a weight not to direct itself towards the center of the earth and to approach this center with its very lowest part.  Therefore, if x did not hang directly under a, x would be approaching closer toward the balance, and this is impossible.