Musical canon wheel, timpani, and notes on the motion of liquids
A reed wheel with 4 teeth as a four-part canon; drums, geometric figures and math
This multispectral image of ff. 137v and 136r sets musical inventions beside notes on physics, and the transcription for the two folios is recorded identically. Above one figure Leonardo describes a 'wheel of canes' with four teeth that acts as a four-voice canon, each tooth standing for one singer, and nearby he notes timpani 'played like the monochord' set to the words «o voi dolze mele». Struck-through lines at the top and inverted along the lower margin argue that the part of a liquid farthest from a denser body (or nearest a rarer one) moves fastest, and a caption points to geometric figures and mathematical operations set out below. The drawings include radiating sunburst wheels, a row of goblets, a bar of musical notation and a large rod carrying a ball.
On this page
Wheel of canes as a four-voice musical canon
Above the figure Leonardo writes that he makes a wheel of canes used like a rack, carrying a musical round called a canon that is sung in four parts. Each of the four singers sings the whole round, so he gives the wheel 4 teeth, each tooth performing the office of one singer. Radiating sunburst wheels on the right sheet illustrate the device.
Timpani played like the monochord
A marginal figure is annotated with the note that timpani, or drums, are to be played like the monochord, set to the words «o voi dolze mele». The words 'the girls' are written beside it. A short bar of musical notation appears among the drawings.
Which part of a liquid moves fastest
A struck-through note reasons that the part of a liquid farthest from the friction of a body denser than itself is the swifter in its motion, while the part nearest the friction of a rarer body is likewise the swifter. The same reasoning returns, upside-down, in the lower margin. It treats the speed of a fluid in contact with denser or rarer bodies.
Geometric figures and calculations
A caption records that geometric figures and mathematical operations are set out below the physics note. The sheet accordingly carries divided circles, sector diagrams and columns of numbers. These accompany the written reasoning.
Rod carrying a heavy ball
A long straight rod runs diagonally across the lower left sheet, ending in a large solid ball, in the manner of a pendulum or weighted lever. It is drawn among the geometric figures without an accompanying transcribed label.