Numerous illus. in text, some using colored ink & four manuscript maps (one is loose). 37; 47; 33; 48 folding leaves. Six parts in four vols. 8vo (270 x 191 mm.), orig. semi-stiff wrappers, old stitching. Izu province: from the final leaf: "copied in 1847." An apparently unique survival of a manual with instructions for naval warfare. Japan in the Tokugawa period maintained strict control of its maritime border, with only Chinese and Dutch merchants being allowed to trade in the port of Nagasaki. Meanwhile, explorers travelled beyond what was then under Japanese control, to northern Hokkaido, Sakhalin, and surrounding areas. In the early 19th century, Japan's geostrategic situation became more complicated with the arrival of Western ships in Japanese waters seeking access to their ports. Several incidents with English and Russian ships led both the shogunal government and many intellectuals to believe that Japan needed stronger coastal defenses and naval capabilities. Our manuscript appears to have been written in this context. The first volume opens with a section on navigation. Different geographical systems are mentioned in the introduction, including the Buddhist cosmology centered on Mt. Meru and the "theory of a moving earth by the Western Classicists," referring to European astronomy as introduced to Asia by the Jesuits. There is also a section on a Dutch theory of the weather. Other topics covered in this section include the tides and navigation by the pole star. The second section treats "using the land to one's advantage" (chiri ??). The third section is concerned with gunpowder and how to make it. Illustrations show different kinds of weaponry, including cannon. The text then discusses Asian and Western military ships, with illustrations of different kinds of oars, rudders, and anchors. Other sections treat, for example, the movement of troops. A large part of the work presents information on naval warfare in question-and-answer format. There is an illustration of a European ship. Several fold-out maps are included in the last volume, one of which locates Japan in its northeast Asian context, with the islands north of Hokkaido and the Manchurian coast shown in some detail. The manuscript was copied in 1847 by one Miyayama Sennosuke ????? in Izu province. The author of the work is given as Tani Sojun. We find no information on him, but the NIJL catalogue lists him as the author of a work on military drills, noting that he belonged to the Yamaga school (Yamaga ry? ???) of military thought. Founded by Yamaga Sok? ???? (1622-85) in the early Edo period, this school sought to fuse the Bushido warrior ethos and military learning. Very good set, preserved in a chitsu. Mostly but not exclusively marginal worming, occasionally touching characters.