Sheet of mechanical devices with Leonardo's signature
Counterweight apparatus, an invocation, the words "Io Lionardo," and a concave-mirror figure
The sheet is densely covered with sketches of mechanisms, including a framed apparatus at the top labelled "counterweight," a spoked wheel, gear trains and assorted contraptions. Among the drawings Leonardo has written an invocation, "In the name of God, amen," at the centre and signed "I, Leonardo" at the lower left. In the lower margin, drawn upside down, is a figure captioned as a concave mirror (speculum). Many further device sketches on the sheet are not covered by the transcription.
On this page
Counterweight apparatus at the top of the sheet
The device drawn across the top of the page is annotated "counterweight," identifying the hanging weight that drives or balances the mechanism. It sits within a rectangular frame together with arcs and a dish-like element.
Devotional invocation
At the centre of the sheet Leonardo has written a short invocation, "In the name of God, amen," a pious formula sometimes placed at the head of a project or notebook.
Signature "Io Lionardo"
In the lower left area the words "I, Leonardo" appear, a rare autograph signature among the working sketches.
Concave mirror figure in the lower margin
Drawn upside down in the lower margin is a figure captioned as a concave mirror (speculum), linking this sheet to Leonardo's studies of curved reflecting surfaces on the neighbouring folios.