Nieuwe verklaring over de proportionaal passer, waar in aangewesen word, hoe dezelve is te tekenen, en hoe tafeltjes daar toe dienende konnen werden berekent, vervolgens der zelver veelvuldig en nuttig gebruyk, zoo in de tel- als meetkonst; ...Amsterdam, Joannes Loots, 1708. 4to. With a large folding engraved plate illustrating the scales on the sector and 12 smaller folding engraved plates showcasing several of the calculations. Contemporary calf, gold-tooled spine.

[4], 72 pp.First edition of "an important Dutch publication on the sector" (Roëll), instructing its reader in the use of the instrument. The sector or proportional compass, a calculating instrument consisting of two rulers joined by a hinge, was invented at the beginning of the 17th century and used for solving a large variety of mathematical problems in gunnery, surveying, navigation and (military) architecture. The author notes in his introduction that he came across a sector, which he thought would be a useful instrument, if it were accompanied by instructions in its use. Since no simple instructions could be found - at least not in Dutch - Warius decided to write his own treatise. After finishing several sets of instructions, he was given a copy of the Tractatus de stylometris (1661/1662) by Nicolaus Goldmann, which also contained instructions for the use of the sector, and he decided to incorporate parts in his own treatise. In the resulting book, Warius first introduces the different scales to be found on the sector, then gives 78 examples of calculations as well as a single example of the construction of a fortress.Pieter Warius (1677-1709) was a notary and mathematics teacher in Oostwoud who besides the treatise on the sector, wrote an introduction to arithmetic.With an owner's inscription on the title-page, corrections possibly made by the same owner throughout the book and a bookplate on the paste-down. Binding worn and damaged, notably at the head and foot, and final 10 pages slightly soiled in the upper margin, but otherwise internally in very good condition.l Bierens de Haan 5256; Roëll, Tekenen ter verlichting, p. 90; STCN (5 copies).