About the author: Warren Dupré Smith (1880 — 1950), worked in the Division of Mines, Bureau of Science, insular government of the Philippines. and the author of numerous studies and reports.

About the diary: Taken from A Geologic Reconnaisance of the Island of Mindanao and the Sulu Archipelago. I. –Narrative of the Expedition. Reprinted from The Philippine Journal of Science, published by the Bureau of Science of the Philippine Government, Manila, P.I., Vol. III, No. 6, Section A, General Science, December, 1908, Manila, Bureau of Printing, 1908.