Oul-neung-to 蔚陵島 朝鮮ノ東海岸ニアリ
Oul-neung-to, Ulleungdo (蔚陵島) sits off the east coast of Joseon (朝鮮)
Ou-san 于山島 朝鮮ノ東方 蔚陵島ノ近傍
Ou-san, Usando (于山島), East of Joseon (朝鮮ノ東方), in the vicinity of Ulleungdo (蔚陵島ノ近傍)
Notice that the gazetter describes Usando as being "in the vicinity of Ulleungdo" (蔚陵島ノ近傍) and gives no coordinates for the island, even though coordinates were given for other islands and places. This suggests that Usando was small enough and close enough to Ulleungdo to not need any coordinates. In comparison, notice, on the same page, the description of Jejudo's neighboring island of Udo (牛島 - 우도), which is 3.5 kilometers off Jejudo's east shore:
Even though Udo (牛島) is only 3.5 kilometers off the east shore of Jejudo (濟州島), its coordinates were given instead of describing it as a neighboring island of Jejudo. This may have been because Jejudo and Udo were much larger islands than Ulleungdo and Usando.
Ou-to 牛島 濟州ノ東方 北緯 33° 23' 東經 126° 50'
Ou-to, Udo (牛島), East of Jeju (濟州) at 33° 23' N, 126° 50' E"
At any rate, this 1894 description of Usando (于山島) is more evidence that Usando was not Liancourt Rocks (Dokdo/Takeshima) since it was described as being near Ulleungdo.