Rotating beam, inclined planes and an irregular pentagon
Mechanics of a beam in a quadrant and inclined planes in a semicircle
The leaf gathers several mechanical and geometric figures in red chalk. At the lower left a beam pivots within a quadrant of a circle, its stations lettered t v, a b n o and p q r S; at the top two semicircles each enclose a triangular inclined plane, lettered f r a n / S t and, in the analogous figure, r S v / x y. A small irregular pentagon is sketched at the lower right.
On this page
Beam rotating within a quarter-circle
A quadrant of a circle is drawn at the lower left with a straight beam pivoting within it, its positions and points lettered t v, a b n o and p q r S. The figure studies how a rotating arm behaves through the quarter turn.
Double inclined plane within a semicircle
Two semicircular figures at the top each contain a triangular inclined plane inscribed within the arc, one lettered f r a n and S t, the other, analogous, lettered r S v and x y. They examine a double inclined plane set inside a semicircle.
Irregular pentagon
At the lower right a five-sided figure is sketched in red chalk, described in the caption as an irregular pentagon. It stands apart from the mechanical diagrams.