1872? Royal Illustrated Atlas - "Islands of Japan"

The following map is entitled "Islands of Japan" and comes from what is believed to be an 1872 edition of "The Royal Illustrated Atlas," which was a British atlas. None of the maps are dated, so the date of the atlas was estimated by using the map of Australia. Also, the map of the United States does not show the state of Colorado. The maps in the atlas are believed to date from 1864 to 1872. You can read more about the map and the atlas HERE. The introduction of the atlas describes the "Islands of Japan" map as follows:

Japan, Mandshuria (showing the course of the Amur River), The Kurile Isles, & c.; according to the British and Russian Admiralty Surveys, Krusenstern, Siebald, & c. By John Bartholomew.  

Section Map.--Port of Nagasaki in the island of Kiou-Siou.  

Illustrations. (1.) View of the Port of Simoneseke, Japan. (2.) Japanese Nobleman and Fisherman. (3.) Japanese women of the higher and lower class. By John Dunlop

The reason I am posting the map is that I think it was mentioned in an 1876 letter written by Watanabe Kouki (渡辺洪基), who was Director of the Bureau of Documents in Japan's Ministry of Foreign Affairs at the time.  Mr. Watanabe was researching the location of Dagelet Island, which was the Western name for Korea's Ulleungdo Island, and he mentioned a map from "The Royal Atlas" as one example of several Western maps that showed Dagelet to be at the coordinates 37 degrees 25 minutes N. latitude and 130 degrees 56 minutes E. longitude.

Mr. Watanabe's letter was entitled "Concerning Matsushima 2, and the Japanese reference in the letter to the atlas was as follows:

英ノロヤールアトラス
Britain's "Royal Atlas"

Mr. Watanabe wanted to confirm the location of Dagelet Island because he suspected the Japanese name "Matsushima" (松島) was being used together with "Dagelet" to refer to Korea's Ulleungdo Island. Traditionally, the name "Matsushima" or "Oki's Matsushima" was used to refer to Liancourt Rocks, which Mr. Watanabe believed to be Japanese territory.

Though it is not 100 percent certain that Mr. Watanabe was referring to this map in his 1876 letter, it quite possible he was since this map does show Dagelet Island in the Sea of Japan. The map also shows an island labeled as "Argonaut," which was a non-existent island that came about due to a mismapping of Ulleungdo by the British Navy.