Lever and balance problems, with a note on aerial perspective
Weights on beams and supports, the fifteenth proposition on weights, and how distance blurs an object's edges
The sheet sets out several statics problems in Leonardo's hand: a rod bent at a right angle and an inclined rod, each loaded with weights, a suspended lever, and a beam resting on two supports whose load is apportioned in the 'fifteenth proposition on weights.' Small diagrams lettered a, b, c, e, K, r, S and t accompany the reasoning. A separate note in the lower right turns to perspective, observing that a 'confused medium' of distance, night or fog makes an object's edges blend into the surrounding air.
On this page
Balancing a rod bent at a right angle
One diagram shows a rod bent at a right angle carrying the labels b, a and c. Leonardo notes that the length a b matches a b c and that the weight is likewise equal, then asks how much weight must be added at e to keep a from sinking downward.
Why a descending weight does not rest beneath b
For an inclined rod labelled a, b, c, n, he observes that the weight c is heavier than b by a small fraction of itself. He asks why, although it stays equally distant from the central line as it descends, the weight does not come to rest directly beneath b.
Fifteenth proposition on weights: sharing a load between two supports
A beam rests on two supports, the nearer a and the farther b, with the load's centre at K. Leonardo argues that a support bears less weight the farther it lies from the load's centre, and works a case in which 8 pounds resolve as five on a and one on b, the projecting parts S r acting as a counterweight that lightens the span by 2 pounds.
Aerial perspective: distance blurs an object's edges
A separate note explains that a 'confused medium' — produced by distance, by night, or by interposed fog between the eye and the object — makes the boundaries of that object appear poorly distinguished from the surrounding air.