Traité de gnomonique MDCCXLIV: Richly illustrated French manuscript on paper

Text written in brown ink with highlights in red and black ink in a neat calligraphic hand. 2 leaves (illustrated half-title and title), 21 numbered text leaves, 1 unnumb. index leaf, 1 multiple folded table "table pour servir à la graduation des fléches", 2 blank leaves. All text leaves ruled by black ink frames. Illustrations: Half-title on recto with large oval medaillon with interlaced strap-work in gold, and year 1745, on verso with a blue rectangle, title in multiple coloured calligraphic script and large rectangle vignette with ornate grey wash-colour ornamentation on a yellow background. 25 plates of which 23 folded, 1 double-page and one full-page with original drawings and diagrams. Four plates with brightly coloured water colour drawings over ink, one full-page plate with a pen and ink drawing of an observatory, twenty plates with ink and grey wash-colour diagrams and sketches. All plates ruled by black ink frames bordered by wide light pink or ocre wash-colour frames. Front wrapper preserved. Stiff cardboard wrapper with dark brown background, ruled by two black ink frames, and four rhombic corner pieces with a red fleur-de-lis design on a yellow background, and a rhombic centre piece with a red flower petal. 4to (310 x 235 mm). Upper left corner with traces of restoration, verso backed. Loose quires in a modern half cloth box.

A complete and richly illustrated French manuscript treatise on sun dials, gnonoms and surveying with instructive and meticulously delineated water colours and grey wash-coloured diagrams and drawings on the plates with designs of different types of dial, both horizontal and vertical sun dials, and with explanations for the use of gnomonic triangles. Paper restoration to upper margins of gutter of a few leaves, light blurring to text on a few pages, but still readable. One plate with restored corner, not affecting image. A remarkably and finely executed manuscript.