75/2481 [Book of secrets]. "Mélange extrait hors différents ouvrages." Manuscript in pen and black and sepia ink, n.pl., n.d. (±1840), 774,(7); (34) (manuscript)p., followed by (198 blank)p., calligraphed title-p., contemp. simple gilt hcalf w. red mor. letterpiece.

= Neatly written manuscript on technical matters, i.a. (as listed in the index): "Algèbre", "Argenture au pouce", "Baromètre à Cadran", "Cadrans Solaires", "Chambre noire ou Obscure", "Compas de Proportion", "Dorure à l'huile", "Dorure sur la tranche des livres", "Echappement d'Arnold à Vibrats. libres", "Gnomonique", "Hijgromètre", "Lacques français", "Papier a Calquer", "Plumes à écrire", "Sphère artificielle ou Armillaire Oblique", and "Zones temperées et Glaciales". The main source for this manuscript appears to be the Dictionnaire technologique ou nouveau dictionnaire universel des arts et métiers, published in Paris in 22 text vols. and an atlas vol. between 1822-1835. Comparison with the original shows that the anonymous author has copied the text literally from the Dictionnaire for the various subjects dealt with. The order in which he has placed the copied sections, however, is not alphabetical and only includes part of the subjects of the Dictionnaire. Possibly the present manuscript was intended to be published as a textbook of sorts, or served a private practical purpose of the author. From the reference on p.94 in the note, it appears that the author had earlier published a work which he refres to as "mon Cours de mathématiques". SEE ILLUSTRATION PLATE CVIII.