This "New Geography" in 1887 by Okamura Masutaro (岡村増太郎『新撰地誌』明治20) (from Waseda University’s site) is a revised edition of 1886’s.
On August 2012, Korean media reported that “Pre-colonial Japanese textbooks mark Dokdo as Korean territory”. However, it’s an another typical false claim by Korean historian.
As you can see, the island they claim “Dokdo” on the map is not Takeshima/Liancourt Rocks but Ulleungdo/Dagelet from its geographic coordinates. And strictly speaking, it is not for sure that this two islands are marked as Korean territory or not. It’s absurd to jump to the conclusion that other country considered them as “Korean” if they are not marked as Japanese territory. (The spot between Oki and Dagelet/Ulleugdo seems to be just an ink blot. )
(Right : GIF animation by O.M.R GT)
Although almost all the maps after 1882 made by the Hydrographic Department of the Japanese Imperial Navy and the General Staff of Office of Japanese Imperial Army blotted out Argonaut, it still remained on many private mapmaker’s maps including textbook or supplementary reader makers, such as Mr. Okamura, wrongfully map Argonaut and Dagelet thoroughout Meiji era. It seems that Ministry of Education were not keen on this issue. In some cases, especially among San-in residents, people’s old recollection of Takeshima/Ulleungdo-Matsushima/Liancourt Rocks combination in Edo era brought slight confusion on the description of those islands in private publication.
However, again, it is not wise to automatically conclude that Japan’s Matsushima was today’s Takeshima/Liancourt Rocks during Meiji or Japan considered Matsushima(=Ulleungdo in Meiji in fact) as Korean. It’s required to be very careful to ascertain what the “Matsushima” or two islands near Korea represent from its geographical coordinates, description of history and whole context of the book, and so on.
What we need is academic/scientific analization. No more propaganda, please.