Many friends have assisted me with correspondence, advice, or help in translation, among whom I must first thank my former students, Haségawa, Hiraii, Haraguchi, Matsui, and Imadatté, and my newer Japanese friends, Ohgimi and Kimura, while others, alas! will never in this world see my record of acknowledgment—K. Yaye′ and Egi Takato—whose interest was manifested not only in discussion of mooted points, but by search among the book-shops in Kiōto and Tōkiō, which put much valuable standard matter in my hands. I also thank Mr. Charles Lanman, Secretary of the Legation of Japan in Washington, for four ferrotypes taken in Seoul in 1878 by members of the Japanese embassy; Mr. D. R. Clark, of the United States Transit of Venus Survey, for four photographs of the Corean villages in Russian Manchuria; Mr. R. Idéura, of Tōkiō, for a set of photographs of Kang-wa and vicinity, taken in 1876, and Mr. Ozawa Nankoku, for sketches of Corean articles in Japanese museums. To Lieutenant Wadhams, of the United States Navy, for the use of charts and maps made by himself while in Corea in 1871, and for photographs of flags and other trophies, now at Annapolis, captured in the Han forts; to Fleet-Surgeon H. O. Mayo, and other officers of the United States Navy, for valuable information, I hereby express my grateful appreciation of kindness shown. I would that Admiral John Rodgers, Commodore H. C. Blake, and Minister F. F. Low were living to receive my thanks for their courtesies personally shown me, even though, in attempting to write history, I have made criticisms also. To Lieutenant N. Y. Yanagi, of the Hyrographic Bureau, of the Japanese Navy, for a set of charts of the coast of Corea; to Mr. Metcalfe, of Milwaukee, for photographs of Coreans; to Miss Marshall, of New York, for making colored copies of the battle-flags captured by our naval battalion in 1871, and for the many favors of correspondents—in St. Petersburg, Mr. Hoffman Atkinson; in Peking, Jugoi Arinori Mori; in Tōkiō, Dr. D. B. McCartee, Hon. David Murray, Rev. J. L. Amerman, and others whose names I need not mention. To Gen. George W. McCullum, Vice-President, and to Mr. Leopold Lindau, Librarian, of the American Geographical Society, I return my warmest thanks; as well as to my dear wife and helpmeet, for her aid in copying, proof-reading, suggestions, and criticism during the progress of the work.