De nieuw uitgevonden sluis met in- en uitschuivende deuren. With: (2) REDELYKHEID, Cornelis. De nieuw uitgevonden diep-machine. The Hague, Hendrik Christoffel Gutteling; Amsterdam, Jacob Yntema & Jacob Tieboel; for the author, 1774. 2 works in 1 volume. Large folio (49.5 x 31 cm). Ad 1 with 6 large folding engraved plates and ad 2 with 3 large folding engraved plates. Contemporary half calf.

XII, 26; XI, [1], 18 pp.Two rare first editions, in the original Dutch, containing detailed descriptions and illustrations of two new inventions in hydraulic engineering: a sluice with sliding gates and a dredging machine. They were designed by the accomplished engineer Cornelis Redelykheid (1728-1788), well-known in his time, but often overlooked in modern literature. The descriptions are accompanied by a total of 9 detailed large folding plates. The dredging machine looks especially ingenious.Redelykheid was already working on his sluice with sliding gates in 1772 and a model was built, one fourth its intended size. The model was inspected and tested by the hydraulic engineer Christiaan Brunings (1736-1805), then inspector general of rivers & waterways, who later founded the Dutch water management department now known as "Rijkswaterstaat". Brunings wrote an extensive and positive rapport on the sluice, which led Redelykheid to be awarded with 1,000 gold ducats by the States of Holland. The award enabled the inventor to publish the present two works at his own expense, both including a preface by Brunings. As a grateful gesture Redelykheid presented the present copy to Brunings, with an inscription on each of the two title-pages.With library stamp and tiny bookplate. Only some minor thumbing in the margins of a few leaves and the leaves facing the plates slightly discoloured where the leaves overlap the fold of the plates, otherwise in very good condition, text leaves untrimmed, leaving wide margins, and with the plates in very crisp impressions. Binding rubbed, with ends of the spine slightly damaged, but still firm and otherwise good.l Bierens de Haan 3902 & 3900; Sloos, Gewapend met kennis, pp. 208-209; not in Roberts & Trent; for the author: NNBW VIII, cols. 1266-1268.