Sighting Instrument: The Eye That Takes Aim
A diagram of a device for aligning the line of sight, with a graduated arc and plumb
A single pen diagram shows a long diagonal line of sight crossing the page and, at the lower left, a small instrument: a ring at the top of an upright with a hanging quarter-circle arc, marked a. The e-Leo transcription labels it the eye that sights, that is, a device for taking aim along a fixed line. The note is written upside down relative to the notebook.
On this page
Device for sighting along a line
At lower left an upright carries a ring at its top and a quarter-circle arc suspended below, labelled a, from which a long straight line runs diagonally across the sheet. The arrangement reads as a sighting instrument for fixing the direction of a line of view.
The eye that sights
The caption describes an eye that sights or takes aim along the line, treating vision as an alignment between the eye and a distant point. The diagram illustrates this act of sighting.