Apparatus for a great ventilator, and pulley-cord levers
A wind-generating machine, concentric circles and squares, and reckoning a cord's lever on its pulley
A large sectional drawing dominates the page: a rounded chamber holding a conical, funnel-shaped valve and, at the right, a piston or screw mechanism in a cylinder, captioned as an apparatus to generate marvellous wind. Beneath the text a small geometric sketch shows three concentric circles with three squares inscribed and circumscribed, alongside a pulley carrying a thick cord. The note explains that when a weight is held by a cord resting over a pulley, one must calculate the levers of the descending and rising cord at the centre of the cord's thickness, as proved on the facing page.
On this page
A machine to generate marvellous wind
The large sectioned drawing is captioned as an apparatus for a great ventilator, meant to generate marvellous wind. A rounded chamber encloses a conical funnel-valve, with a cylinder and piston or screw mechanism worked at the right.
Reckoning the lever of a cord on its pulley
When a weight is held up by the cord resting over the pulley, one must calculate the lever of the descending cord together with the lever of the rising cord, at the contact with the pulley or at the centre of the cord's thickness. It is to be reckoned at the centre of the cord, as proved on the reverse of this page.
Three concentric circles and squares
A small diagram shows three circles and three squares set concentrically, inscribed and circumscribed one within another. It accompanies the note on the pulley cord without a text of its own.