There is an island at 40-ri north from Nisji-jima *
(western island) of Oki county's Matsushima, which is called Takeshima. This
island is close to Japan and is next to Chosun, and its shape is triangular with
the circumference about 15-ri.
(*Nishi-jima: a small islet which belongs to Matsushima. People in this area usually call it as "Tsugi-no-shima", the next island.)
ca 1840-1860 Matsushima of Oki County
To follow is from the book 文鳳堂雑纂 (Compilation of various things by Bun-ho-do) by Bun-ho-do (文鳳堂) aka Yamashiroya Chubei (山城屋忠兵衛), who was a scholar in the late Edo period. The exact published date is unknown but it may have been mid to late 19th century - perhaps 1840-1860.
In the chapter of Takeshima (Ulleungdo), he referred to Matsushima (Liancourt rocks) as Oki county's Matsushima. This is another evidence to show that Japanese in the Edo period believed that Matsushima (Liancourt rocks) was a part of Oki county.
(The map of Ulleungdo is from this book.)