Method for the waters, a roller gear and a columned frame
A reminder to put experience before reason when studying water, above a helical-geared roller and a pair of columns on triangular framing.
The three lines of pen writing at the top remind Leonardo to cite experience first and reasoning afterward whenever he treats of the waters. Below, in red chalk, is a mechanism of paired rollers driven through a helical (worm-gear) coupling. A second red-chalk study at the foot shows two columns carried on triangular bracket-framing beneath a lintel.
On this page
Rollers with a helical drive
The upper red-chalk drawing sets out a machine of paired rollers or drums engaged through a helical, worm-like coupling. The caption names it a roller mechanism with helical-pair transmission; no explanatory text accompanies the sketch.
Columns on triangular framing
The lower red-chalk drawing shows two vertical columns standing under a horizontal beam, each seated on a triangular bracket or trestle. It is captioned as a pair of columns supported by triangular framing.
Experience before reason in studying water
The pen note reminds the writer that when he comments on the waters he should cite the experience first and the reasoning only afterward. It states a method for hydraulic study rather than a specific result.