Gunter's rule with sailing lines. All edges are sloped. On 1 face is a typical Gunter's scale, with an additional line of chords on the same parallel as the sines of rhumbs. On the other face, a 24-inch scale (0-24, by 1, decimally subdivided) reads to the edge. Radiating from the 12-inch mark are lines lettered with compass directions for use in sailing. A horizontal double-line cuts across the sailing lines with lettering on the upper and lower section.
Materiaal
"*LADY OF St. KILDA YACHT*; *T.D.A. 1837*; *CARY LONDON*"
upper section: "THESE LETTERS SHEW THE BEARING OF THE SCALE WHEN THE COMPASS LINES ARE APPLIED TO A MERIDIAN ON THE CHART."
lower section: "THESE LETTERS SHEW THE SAME WHEN THE LINES ARE APPLIED TO A PARALLEL OF LATITUDE."
