[Mills] "Aanleidinge tot de Kennis en het Maaken van een Gewoone Scheprad Watermolen:

Waar door men volgens eene Alphabetische orde zeer gemakkelyk kan naagaan de Samenstelling en Opbouw vaan zoodanig Werktuig (...). Cornelis de Graat Oud 71 Jaaren MDCCLXXXVI." Manuscript consisting of a title page, 93 leaves written mostly on one side and several unwritten leaves, with folding cross-section of a mill in pen and ink and hand-coloured with yellow watercolour, furthermore 5 illustrations in pen and ink (3x greywashed 1x also with pink watercolour) and 1 (very vague) illustration in pencil, all on reverse of text pages, contemporary marbled cardboard, 24.3 x 19.5 cm.

On the title pages addenda are mentioned which are not included. Else in perfect condition. According to the work "Mathematische Liefhebberye, met het nieuws der Fransche en Duytsche schoolen in Nederland" (published from 1754), Cornelis de Graat was in 1741 "Geadmitteert landmeeter" and schoolmaster in Langeraar and Korteraar. Additionally, two manuscript maps by De Graat are known, concerning among other things the reclamation of polders. In this highly extraordinary manuscript, as announced by the title, all terms related to the fabrication of a water mill are explained in an alphabetical list. In various places there are also complex mathematical equations, for example with the term "Molenreekening", below which no less than 22 pages of calculations can be found. Two fine illustrations have been added to the term "Scheprad" (5 p.).