Codex Forster II (National Art Library, Museum no. MSL 1876 Forster 141 II)

Codex Forster II is made of two notebooks bound together. Both were compiled in Milan, while Leonardo was in the service of the duke of Milan, Ludovico Sforza (1452 – 1508). The first notebook (up to folio 63, about 1495) contains notes and diagrams on the theory of proportions, but also miscellaneous sketches, including frames for weaving (folios 49 verso – 50 recto), architecture (as on folio 52 recto) and some figurative drawings such as a Virgin and Child (folio 37 recto). The second notebook (from folio 64, about 1495 – 97) includes notes on the theory of weights and balances, as well as sketches on perpetual motion (as on folios 90 verso – 91 recto), drawings of helmets (folio 65 recto), and a recipe for making paints (folio 159 recto).
As Leonardo wrote in mirror writing (in reverse and from right to left) he often started with what we would consider the last page. This can be seen in the second notebook where Leonardo himself numbered the folios from 1 (folio 158 verso) to 94 (folio 65 verso).