Among visitors who contributed to the Observatory work were Sidney Powers, a voluntary observer who had been one of my students in Boston. He explored and published on many volcanoes around the world and followed me in Sakurajima and the Aleutian Islands. He later became an outstanding petroleum geologist of the Amerada Company in Tulsa. Arthur Hannon, an architect from Cleveland, acted as a volunteer mapper, and for months aided with sketches of the changes in Halemaumau. William Twigg-Smith, an artist from New Zealand, joined us in the lava-sounding experiment and made numerous sketches and paintings. He later became the illustrator and photographer for the Hawaiian Sugar Planters’ Association. Dr. A. L. Day of the Geophysical Laboratory visited us repeatedly, in association with gas chemist E. S. Shepherd. He wrote important monographs, along with E. H. Allen the chemist for the Carnegie Institution, on the Yellowstone and Lassen National Parks, and on Geyserville. Allen came to the Observatory for critical analysis of the steam of Sulphur Bank. Among other visitors were geologists, geodesists, and biologists of the Pacific Science Congress, held in the spring of 1920. These included H. E. Gregory, Griffith Taylor, Frederick Wood-Jones, William Bowie, T. W. Vaughan, E. O. Hovey, E. C. Andrews, F. Omori, H. S. Washington, and Dr. Chilton of Christchurch, who had been one of our inspirers in the New Zealand trip. This Honolulu world congress assigned one meeting to Kilauea Volcano, which enabled me to summarize results before a cosmopolitan group of scientists. The Washington executives who at this time promoted the Observatory were Secretary of Agriculture David F. Houston, Director George Otis Smith of Geological Survey, Chief Charles Marvin of the Weather Bureau, and Charles D. Walcott, Secretary of the Smithsonian. Later came W. C. Mendenhall, firm friend of the Observatory, and Director of the Survey. It was my good fortune that between 1914 and 1919 Mauna Loa and Kilauea were building up lava toward a fiery crisis, and that the sugar business of Hawaii boomed at the same time. When the 1920 science congress convened there was much fresh lava to be seen, and our Research Association was so prosperous that M. I. T. in Boston kept up its financial interest. The _American Journal of Science_ under Edward Dana of Yale published our results. This was fitting, as Dana’s father, J. D. Dana, had published much about Hawaiian volcanoes. Consequently the end of the foundation decade made easier the financing of the next five years. Just at this time the Geological Survey spurted ahead, the National Park was opened, the Army built a recreation camp and a trail up Mauna Loa, the Inter-island Steamship Company took over the Volcano House, and a Promotion Committee was bringing many tourists.