Perspective rule, arches, a pile-driver and its costs
A surface looks true only from equal distance; the itemized price of a pile-driving rig
The page mixes theory, drawing and reckoning. A pen note on perspective holds that no surface appears undistorted unless the eye is equally distant from its edges; red-chalk arches and a pile-driving device fill the sheet. In the margin Leonardo itemizes the cost of the rig's parts — wheel, mast, shield, carriage, mast-piles, bed and frame, channel — totalling 71 lire. A further line observes that the wave of coarse sand rises more gently and slowly than it falls.
On this page
A surface looks perfect only from equal distance
Under the heading 'Perspective', Leonardo states that no surface will appear perfect (undistorted) unless the eye beholding it stands equally distant from its extremes. It is a rule for foreshortening in painting.
Pile-driving equipment
A device for driving piles is drawn at the right, a weight raised on a frame over its guide. The note simply labels it pile-driving equipment.
Itemized cost of the pile-driver, 71 lire
Leonardo prices the parts of the rig: the wheel 7 lire, the mast 10, shield 4, carriage 8, mast-piles 2, bed and frame 30, and channel 10 — 71 lire in all. The tally reads as a builder's estimate for the machine.
Figures of arches
Several arches are sketched in red chalk across the upper sheet, noted only as figures of arches.