Proportion of powder and barrel in a small firearm
A rule that more powder shortens the useful barrel length, with proportion notes
A red-chalk page headed with the words 'Proportion' and 'Proportionality' followed by the short number series 1 2 and 1 2 3. The main note is a rule of thumb: the more powder packed into a small firearm (scoppietto), the shorter the effective length of its barrel becomes, so one must attend to the proportion of forces involved. Further numerals and jotted words appear lower on the sheet beyond the transcribed lines.
On this page
Rule linking charge of powder to barrel length in a scoppietto
Leonardo advises that the more powder is loaded into the small firearm, the more the working length of the barrel is reduced. He warns the reader to keep this in mind when reckoning the proportions of the forces (powers) at play. It reads as a practical ballistics maxim rather than a calculation.
Headings 'Proportion' and 'Proportionality' with number series
The page opens with the labels Proportion and Proportionality set beside the short sequences 1 2 and 1 2 3. These frame the firearm note within the notebook's running study of proportion. Additional numerals recur lower on the leaf.