東の海
The first detailed study of the Mare Orientale was by Hugh Percy Wilkins, who called it "Lunar Mare X". Franz's discoveries were not well known, and in the 1976 edition of his book "Guide to the Moon", Patrick Moore claims that he and Wilkins discovered and named Mare Orientale in 1946. However, Moore credits Franz as discoverer in his "2009 Yearbook of Astronomy" (p. 133-135).