Tavole gnomoniche per delineare Orologi a Sole (Gnomonic Tables for the Construction of Sundials) [AND] Tavole per regolare di Giorno in giorno gli Orologi (Tables for Setting the Sundials on a Daily Basis)

Bologna: Lelio dalla Volpe, 1733. First edition. Hardcover. Nearly Fine. Two jointly-issued works bound in one volume, published in 1733 and 1736, quarto. [pi]2, A-2D4 2E2 (=112 leaves). [4], 220pp.; A4 [chi]2 (=6 leaves). 11, [1, imprimatur]pp. Title of the Tavole gnomoniche in red and black; large engraved vignettes at titles of both works. N.B.: The 12-page Tavole per Regolare has been bound-up preceding the six engraved plates of the main text.The six unsigned folding engraved plates which accompany the Tavole gnomoniche are bound following the Tavole per regolare. Contemporary vellum Over lightweight boards, manuscript title with remnant of gilt border at spine. Headcap worn. Neat Ex libris stamps at front and rear endleaves; manuscript imprimatur at title of the first work. Old ink stain in margin C2 (not impairing legibility), else a fine, amply-margined, crisp and clean.

First editions of two uncommon works on sun-dials published between 1733 and 1736, written by the architect and engraver Giovanni Lodovico Quadri (1700-48). Montucla (Historie des mathematiques, vol. 1, 732) considers Tavole gnomoniche one of the most important books on the subject. The work attempts to abbreviate the calculations necessary for the positioning of sundials by the use of gnomonic tables, "in which the height of the pole on the plane which must receive the sundial is given, along with the declination of the plane and its inclination, so one can find in decimal parts of the radius the tangents of the hour angles from noon." Earlier examples of this procedure appear in Hyppolytus Salodius' Tabulae gnomonicae (Rome, 1617); and Carlo Maria Caraffa's enormous folio for both italic and astronical sundials, Exemplar horologiorum solarium civilium (Mazareni, 1689).

Provenance: contemporary monastic library inscription (perhaps Jesuit) at the foot of the title; recent ex libris stamps of Christopher St. J.H. Daniel. Full titles: Tavole gnomoniche per delineare orologi a sole, che monstrino l'ore conforme a quelle degli orologj, che suonano con altre tavole che servono per la construzione de' medesimi, e per altri usi calcolate da Gio: Lodovico Quadri assoccioato all'Accademia dell'Instituto delle Scienze di Bologna. In Bologna nella stamperia di Lelio dalla Volpe. MDCCXXXIII. Con licenza de' superiori. [AND] Tavole per regolare di giorno in giorno gli orologj a ruote, tanto per adoperarli secondo l'uso d'Italia, quanto per valersene secondo quello degli Oltramontani, con ana tavola perpetua del principio dell'Aurora, levar de Sole, mezzo giorno, e mezza notte; le quali tavole sono come appendice alle Gnomoniche di Gio: Lodovico Quadri. In Bologna nella stamperia de Lelio dall Volpe. MDCCXXXVI. Con licenza de' superiori.

References: Riccardi I, 325. Sotheran, First Supplement, 2926.