Weight on the feet, speed of motion, and how animals walk
The standing figure's balance, the centre of gravity, and the gait of four-footed animals
This treatise page analyses how a standing man distributes his weight over his feet, distinguishing natural weight from natural weight mixed with accidental weight, and promises a separate book on this 'ponderation'. A chapter on local motion states that the speed of a man or animal grows or lessens as the centre of gravity moves further from or nearer to the supporting foot. A further chapter explains that four-footed animals rise in height as they walk because their slanting legs straighten to the perpendicular, and the page ends by opening a discussion of the correspondence between the two halves of the body. A small pen sketch of a four-footed animal is drawn within the text.
On this page
Speed of local motion and the centre of gravity
The chapter 'Of local motion, more or less swift' states that the movement of a man or any other animal is faster or slower in proportion as the centre of its gravity is more remote from, or nearer to, the centre of the foot on which it supports itself. It ties bodily speed directly to the placement of the centre of gravity.
Equal and unequal loading of the feet
A man standing still loads each foot either equally or unequally. If equally, he bears either simple natural weight or natural weight mixed with accidental weight; only under simple natural weight are the opposite extremities of the limbs equally distant from the joint of the foot. Leonardo promises a separate book on this ponderation.
How four-footed animals rise as they walk
The greatest height of four-footed animals varies more in those that walk than in those standing still, and more or less according to the animal's size. This is caused by the obliquity of the legs touching the ground, which raise the animal's body when those legs undo their slant and stand perpendicular.
Pen sketch of a four-footed animal
A small ink drawing of a four-footed animal, resembling a horse or similar quadruped shown in profile, is set within the lower text column beside the discussion of how such animals move. It illustrates the accompanying chapter on the gait of four-footed beasts.