Disjunct proportion: the series 6, 8, 9, 12
Red-chalk numbers and paired figures illustrating disjoined proportion
In red chalk Leonardo sets out the proportion series 6, 8, 9, 12 along a ruled line and repeats the numbers inside two overlapping lens-shaped figures below. The note labels the relation 'disgiunta' (disjoined) and reduces it to the ratios 6:8 and 3:4, with 18 written twice. Two small stacked fractions appear at the foot of the page. Additional faint mirror-script above these fractions is not included in the transcription.
On this page
The disjoined series 6, 8, 9, 12
The numbers 6, 8, 9, 12 run along a single ruled line and are repeated within two joined lens-shaped figures beneath it. Leonardo calls the relation 'disgiunta' (disjoined) and reduces it to the ratios 6:8 and 3:4. The value 18, written twice, marks a shared sum or term of the proportion.
Ratios written as fractions
At the foot of the sheet the transcription records the pairs 6, 8 and 3, 4, set down on the page as small stacked fractions. They restate in fraction form the proportional terms explored in the figures above.