Instruments for orientation: a level, a sundial and a bell device
Small red-chalk instruments captioned to keep straight, to measure the sun's altitude, and to know one's place
The leaf, drawn inverted in red chalk, gathers several small measuring instruments each with a terse caption of its purpose. A level is captioned "to go straight"; a sun-and-meridian device "to measure the degrees of the sun's altitude"; a lower figure "to know better"; and an instrument fitted with a bell "to know well where I am". Faded further figures and a fragment reading "ri" remain toward the centre.
On this page
A level, to keep straight
One instrument is a level (livella), captioned with its use, to go straight, i.e. to hold a true line or horizontal.
Sun and meridian: measuring the sun's altitude
A device combining the sun with a meridian line is captioned to measure the degrees of the height of the sun, a sundial-like means of taking the solar altitude in degrees.
A bell-fitted instrument, to know one's place
An instrument furnished with a bell is captioned to know well where I am, a device for orientation or position. A further indeterminate figure is captioned simply to know better.
Indeterminate figure, to know better
A lower, indeterminate figure carries the caption to know better, evidently another aid to observation or measurement.