The sinew which guides the leg, and which is connected with the
patella of the knee, feels it a greater labour to carry the man
upwards, in proportion as the leg is more bent; and the muscle which
acts upon the angle made by the thigh where it joins the body has
less difficulty and has a less weight to lift, because it has not
the [additional] weight of the thigh itself. And besides this it has
stronger muscles, being those which form the buttock.

379.

A man coming down hill takes little steps, because the weight rests
upon the hinder foot, while a man mounting takes wide steps, because
his weight rests on the foremost foot.

[Footnote: See Pl. XXIII, No. 4.]

On the human body in action (380-388).

380.

OF THE HUMAN BODY IN ACTION.

When you want to represent a man as moving some weight consider what
the movements are that are to be represented by different lines;
that is to say either from below upwards, with a simple movement, as
a man does who stoops forward to take up a weight which he will lift
as he straightens himself. Or as a man does who wants to squash
something backwards, or to force it forwards or to pull it downwards
with ropes passed through pullies [Footnote 10: Compare the sketch
on page 198 and on 201 (S. K. M. II.1 86b).]. And here remember that
the weight of a man pulls in proportion as his centre of gravity is
distant from his fulcrum, and to this is added the force given by
his legs and bent back as he raises himself.

381.

Again, a man has even a greater store of strength in his legs than
he needs for his own weight; and to see if this is true, make a man
stand on the shore-sand and then put another man on his back, and
you will see how much he will sink in. Then take the man from off
his back and make him jump straight up as high as he can, and you
will find that the print of his feet will be made deeper by the jump
than from having the man on his back. Hence, here, by 2 methods it
is proved that a man has double the strength he requires to support
his own body.

382.

OF PAINTING.

If you have to draw a man who is in motion, or lifting or pulling,
or carrying a weight equal to his own, in what way must you set on
his legs below his body?

[Footnote: In the MS. this question remains unanswered.]

383.

OF THE STRENGTH OF MAN.

A man pulling a [dead] weight balanced against himself cannot pull
more than his own weight. And if he has to raise it he will [be able
to] raise as much more than his weight as his strength may be more
than that of other men. [Footnote 7: The stroke at the end of this
line finishes in the original in a sort of loop or flourish, and a
similar flourish occurs at the end of the previous passage written
on the same page. M. RAVAISSON regards these as numbers (compare the
photograph of page 30b in his edition of MS. A). He remarks: "_Ce
chiffre_ 8 _et, a la fin de l'alinea precedent, le chiffre_ 7 _sont,
dans le manuscrit, des renvois_."] The greatest force a man can
apply, with equal velocity and impetus, will be when he sets his
feet on one end of the balance [or lever] and then presses his
shoulders against some stable body. This will raise a weight at the
other end of the balance [lever], equal to his own weight and [added
to that] as much weight as he can carry on his shoulders.

384.

No animal can simply move [by its dead weight] a greater weight than
the sum of its own weight outside the centre of his fulcrum.

385.

A man who wants to send an arrow very far from the bow must be
standing entirely on one foot and raising the other so far from the
foot he stands on as to afford the requisite counterpoise to his
body which is thrown on the front foot. And he must not hold his arm
fully extended, and in order that he may be more able to bear the
strain he must hold a piece of wood which there is in all crossbows,
extending from the hand to the breast, and when he wishes to shoot
he suddenly leaps forward at the same instant and extends his arm
with the bow and releases the string. And if he dexterously does
every thing at once it will go a very long way.

386.

When two men are at the opposite ends of a plank that is balanced,
and if they are of equal weight, and if one of them wants to make a
leap into the air, then his leap will be made down from his end of


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