A striking water-clock that sounds the twenty-four hours
Cisterns filled and emptied by floats trip a hammer against a bell
The sheet is packed with sketches and two columns of notes for a water-driven clock that marks and sounds the hours. Twenty-four small cisterns (bottini) are filled in turn by a channel; as each fills, a rising float (baga) releases a hammer that strikes a bell, whereupon the cistern's bottom opens and it empties to reset. Interspersed are physical observations on softened percussion and on impetus carrying an inert body into motion, plus a short column of figures.
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A clock that marks and sounds the twenty-four hours
A clock displays the hours outside and raises twenty-four floats over twenty-four hours; each float unlocks the cistern that sounds the hour. When a cistern is full, a small joined vessel governed by the 'rule of the sixth' opens and pours out its water.
Float, hammer and the self-emptying cistern
The float d e rises at once to the water's surface when released, by means of the rising float n m. The hammer strikes, and in striking the front of its case opens so the water pours out and immediately closes again. Letter labels: o, d, n, p, m, a, e, b.
Hammer struck upon a spring to keep the bell ringing
When the hammer strikes the bell it strikes with its handle upon a spring, so the blow does not rest on the bell and choke the sound after the stroke. The same handle is arranged so that, once it has sounded, it also unlocks the cistern.
Softened percussion and the impetus of motion
Falling in several successive motions makes the percussion almost imperceptible, as a brick struck in the hand breaks yet does no harm. The impetus of a moving part carries with it the greater part that was at rest, as when a person rises: while moving from the knees up the legs stay still, then follow.
Column of figures
A short worked column of numbers stands beside the clock notes, apparently tallying the hourly cisterns and their fillings. The figures run 10, 6; 5; 2; 1; 12; 1; 1; 1; 36, 6.
