In the book, he said that the eastern limit of Korea's border was at 130°35’E. That suggests that Sewaki believed Liancourt Rocks (Takeshima/Dokdo) to be outside Korean territory.
The following is an excerpt from the book:
The country of Joseon is located in northeast Asia. The shape is a peninsular sticking into the Pacific Ocean. The latitude starts from 34°17’ north of the equator and stops at 43°2’. The longitude starts from 124°30’ east of Greenwich, England and stops at 130°35’.
This is the oldest Japanese book found so far to mention the latitude and longitude of Joseon Korea. Many books followed his writing style later on, but, unfortunately, there is no information on what sources Sewaki used to quote Joseon Korea's longitude and latitude.
The "Keirinjiryaku" was co-authored by Hayashi Shinzo (林深造). This is an encyclopedic book on Joseon that consists of two volumes. The first volume contains such general information as geography, customs, and population. The second volume focuses on military information.
A Mr. Kim In-seung (金麟昇) helped Hayashi by gathering and selecting Joseon books for references. Mr. Kim, who was from Gyeong-heung-bu in Joseon's Hamgyeong Province (咸鏡道慶興府) got acquainted with Sewaki in Vladivostok, but he later stayed in Tokyo with the help of Sewaki. Interestingly, Sewaki and Kim co-authored "The Full Map of Chosun（朝鮮国全図)", which depicted Usando (于山島) to the west of Ulleungdo (鬱陵島).
Sewaki is also known for having submitted, from Vladivostok, the request applications to develop Matsushima (松島), which resulted in the compilation of the "Takeshima Kosho (竹島考証)" between 1876 and 1877.
Kido Takayoshi (木戸孝允), who played a large role in the establishment of the new Meiji government, wrote the title for Sewaki's book. Mr. Kido was one of many students who had attended Sewaki 's private English school.