The Korean ministry replied that the county was established on October 25, 1900, and that the neighboring islands were Jukdo (竹島) and Seokdo (石島). The Korean ministry also gave the dimensions of Ulleungdo as being sixty ri from east to west and forty ri from north to south for a total of 200 ri. Since a Korean ri was 0.4 kilometers, that means Uldo County was defined as having an area of 24km x 16km.
The 200 ri figure referred to the perimeter of the county (60 + 60 + 40 + 40 = 200), which converts up to 80 kilometers.
This article is very important in the Dokdo/Takeshima debate because it is evidence that the Korean government in 1906 did not recognize "Dokdo" (Liancourt Rocks) as being part of Uldo County since Dokdo is about 90km southeast of Ulleungdo.
It is quite probable that the Japanese request for clarification of the neighboring islands of Ulleungdo was caused by recent Korean newspaper reports saying that Japan had incorporated an island named "Dokdo" (Liancourt Rocks), which the Uldo County Magistrate thought was part of his county, even though he did not know exactly where it was. Since the magistrate had been ordered by his superiors to confirm the status of Dokdo, and since the Korean government did not include Dokdo in their reply to the Japanese request months later, we can assume that the investigation revealed that Dokdo was not a part of Ulleungdo.
The article was apparently discovered by a Mr. Sugino Yomei (杉野洋明), who wrote about it in Japanese on his site HERE. Below is the article and my translation. The newspaper page the article came from can be found HERE:
Facts on Arrangement of Uldo CountyThe Resident-General sent an official letter to the Interior Ministry asking it to clarify what islands belonged to Ulleungdo, which is under the administration of Samcheok County in Gangwon Province, and the year and month the county office was established. The response was that the post of Ulleungdo Administrator was established on May 20, 1898, and then on October 25, 1900, the government decided to post a county magistrate with the county office being at Daehadong (台霞洞). It said the islands under the authority of the said county were Jukdo (竹島) and Seokdo (石島), and that it was sixty ri from east to west and forty ri from north to south for a total of 200 ri.
統監府에서 內部에 公函하되 江原道 三陟郡 管下에 所在 鬱陵島에 所属島嶼와 郡廳設始 年月을 示明하라는 故로 答函하되、光武二年五月二十日에 鬱陵島監으로 設始 하였다가 光武四年十月二十五日에 政府會議를 經由하야 郡守를 配置하니 郡廳은 台霞洞에 在하고 該郡所管島는 竹島石島오、東西가 六十里오 南北이 四十里니, 合 二百餘里라고 하였다더라.