Machine to Make Spheres, with an Alloy Recipe
A turntable device that will make spheres of every kind, plus an iron centering and a casting mixture
The sheet is dominated by a large machine built on a table with a rotating turntable and a curved iron centering, which Leonardo says will make spheres of every kind, adding the word firmament. To the left he labels the iron centering (centina). Below, a metallurgical note prescribes putting tamarso and tin into the mixtures, or else removing the usual mixture and adding enough arsenic to break it down, while a top-margin memorandum reads simply the chained books.
On this page
Machine to make spheres of every kind
Leonardo writes that the machine will make spheres of every kind, adding the word firmament. The large drawing shows a turntable mounted on a table, worked against a curved guide to form spherical bodies.
The iron centering (centina)
A label at the left identifies the iron centering, the curved rib that guides the shaping of the sphere. It corresponds to the arced iron member drawn across the machine.
Alloy recipe with tin and arsenic
A note prescribes putting tamarso and tin into the mixtures; failing that, one should remove the usual mixture and add so much arsenic that it corrupts it. The recipe concerns the metal alloy used in the work.
Memorandum: the chained books
A brief note in the upper margin reads the chained books, apparently a reminder unrelated to the machine below.