Reducing a solid to a perfect cube; a red-chalk mechanism
Geometry of cubes and parallelepipeds on one fragment, a machine sketch on the other
This mounted leaf carries two fragments. The smaller (sheet 927a) is filled with studies of cubes and parallelepipeds labelled a and b, where Leonardo asks by how much he must lower a body to make it a perfect cube, halves and obliquely cuts solids, divides a parallelepiped into unit cubes numbered 6 to 1, and jots the cancelled numbers 3 and 27. The larger fragment (sheet 927b) is drawn in red chalk with a mechanism and, per the transcription, bears no writing.
On this page
Reducing a solid to a perfect cube
A parallelepiped and cube are marked a and b, and Leonardo asks by how much he must lower the body to turn it into a perfect cube. Further sketches halve the figures across the diameter (c, e; f) and cut a cube obliquely along the labels b-a-d-c.
Cube numbers and unit division
One sketch divides a parallelepiped into a row of unit cubes numbered o, 6, 5, 4, 3, 2, 1, and the oblique-cut cube is reasoned with equal edges of 10. At the foot the cancelled numbers 3 and 27 record a cube and its cube root.
Red-chalk mechanism (sheet 927b)
The larger right-hand fragment is drawn in red chalk and shows a long horizontal mechanism with a disc or wheel and a framed body pierced by a row of holes. The transcription notes this fragment carries no writing.