Center of gravity of solid bodies
Wedges, cones and faceted solids, with the general rule for their balance point
Studies of the center of gravity in solid figures, drawn as lettered wedges, cones and pyramids threaded with internal construction lines. Leonardo notes that a wedge (bisconeo) has its center of gravity at the middle of its length and toward the quarter of the axis of its triangle, and one figure explicitly labels the 'centro di gravita'. The sheet closes with a general rule: the center of gravity of any faceted body lies where the axes rising on the intersected lines from its angles cross.
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General rule for the center of gravity of a faceted body
The center of gravity of any faceted body lies at the intersection of the axes born upon the intersected lines that set out from the angles of its sides. This is the governing principle the individual figures illustrate.
Center of gravity of a wedge
This wedge (bisconeo) has the center of its gravity at the middle of its length; because a b relates to a d c, the center still falls at the quarter of the axis of its triangle a d c b. The figure is lettered o, a, m, c, p, n, q, d, r, b.
The cone
Turning the sheet, a lettered figure f-m n is captioned simply 'Here is the cone', one of the solids whose balance point is under study alongside the pyramids and wedges.
A base shared by two triangular solids
In the lettered figure e f-b c-d a marked 'center of gravity', the base e b d is common to two triangles, one of four bases and the other of five. The construction compares how the shared base positions each solid's balance point.