Hoisting a great weight and the squaring of triangles
Lifting frames, a needle-sharpening machine, quadrature figures and a calculation
The upper sheet shows braced timber hoisting frames and a suspended block, with a note directing that a foundation first be laid at point b and a very great weight then lowered onto the prepared support a. Across the centre run long horizontal mechanisms, catalogued by the Ambrosiana as a needle-sharpening machine and its driving belt. The lower half carries geometric figures for the quadrature of curvilinear triangles, a caption that squaring is 'done by motion', and a small column of figures. Additional faint writing appears on the sheet that is not transcribed in this bundle.
On this page
Setting a great weight upon a prepared foundation
A note beside the lifting frames directs that the plinth first be established wholly above ground with a sufficient foundation at point b. The beams that had raised the maximum weight by degrees are then removed, and that great weight is lowered onto the already-established support a.
Needle-sharpening machine and driving belt
Long horizontal mechanisms span the middle of the leaf, one a raised beam device and another a train of upright pins or rollers. In the Ambrosiana classification these are identified as a machine for sharpening needles together with its driving belt.
Quadrature of a double curvilinear triangle
Around a paired curvilinear triangle Leonardo states that the two triangles are each double the other. Square the excess that the greater has over the smaller and you have squared the smaller; add an equal square again and you have squared the whole large triangle.
Squaring performed by motion
A short caption on the descending right side labels one construction 'squaring done by motion', pointing to a kinematic method of quadrature.
A column of figures
In the upper-left corner a small stack of numbers (64, 8, 2) opens a calculation, broken off after the words 'If the...'.