It was necessary to keep track of improvements in photographic plates, for the fire pit with its dark red heat and dark red rocks was a difficult subject for photography. Fortunately, the panchromatic plate had recently been invented by Dr. C. E. K. Mees, and was a godsend for experiments in recording liquid lava splashing at night. Dr. Mees, chief of research at Eastman Kodak Company in Rochester, has since been a visitor and good friend of the Observatory. Both surveying and photographing were difficult during 1912 because the inner pit sent up a dense column of fume which diminished only at those times when the liquid lava became hotter and developed fountaining. There was such smokeless development with hundreds of roaring fountains of liquid lava in January and July. The intervening period showed a great deal of smoke, and in August there was a dense column of silently rising gray fume the full width of the pit, so that nothing of the bottom could be seen.
To determine the height of the bottom lava it was necessary to work from a fixed station with a transit, using a flashlight at night, and waiting for a view of a glowing spot or fountain. This involved reading vertical and horizontal angles, dependent on difficult determination from two stations, of the distance to the glow spot measured. Often in daytime one had to wait hours in order to get a view of the bottom through the fumes, from stations at the ends of a base line on the edge of the pit. At no time later, fortunately, were the fume conditions so bad as during 1912. A procedure was adopted of making a daily photograph of the smoke of the distant pit from the window of the observatory, and this proved of value when the inner lava lakes and crags rose to view in 1917.
Like Perret, I made reports to the newspapers in Honolulu; and gradually these reports took the form of a monthly bulletin, edited in Honolulu by Dr. Howard Ballou, who was the secretary of the Hawaiian Volcano Research Association. This association had occasional Directors’ meetings, which I attended and before which I made reports and gave lectures. The report of the complete work done during the first few months of the year 1912 was published in Boston by Massachusetts Tech.
The earlier history of Hawaiian volcanoes had been recorded in excellent books by such travelers as the Misses Gordon-Cumming and Isabella Bird, William Lowthian Green, and Drs. C. H. Hitchcock and W. T. Brigham, and Professor James D. Dana of Yale. Dana had been furnished with data from 1840 to 1890 by a Hilo missionary, Titus Coan. When I arrived in Hawaii, two books on Kilauea’s activity in 1909 had just been published, and a big monograph by Brun of Geneva who had determined that Kilauea lava was free from water vapor and was the hottest lava in the world.
Furthermore, R. A. Daly of Harvard had published his “Nature of volcanic action” on the basis of his summer at Kilauea in 1909. There was strong controversy against Brun on the water question, but the experts, including Day and Shepherd, came to the conclusion that lava eruption of the Kilauea type was actuated by such flaming gases as hydrogen, carbon monoxide, and sulfur; that these gases were in solution in some elemental form deep down in the earth; and that the chemistry of their emission heated the lava on its way up. The lava lakes were hotter at the top than at the bottom. We shall see that all lava partly solidifies at its own bottom and stays liquid above.
The items of activity at Kilauea Volcano during the decade from 1911 to 1920 were marked fluctuation up and down in 1912–1913, with a notable low level in 1913, culminating in a strong earthquake in October. In 1914 the liquid lava came back into the bottom of Halemaumau pit, and in December Mauna Loa erupted in a fountain at its summit crater. The lava lakes of Kilauea grew bigger in 1915, and a triangular island appeared, lifting itself up from a shallow flat and even rotating or hinging horizontally. Its uplift was as a peaked escarpment of lava layers tilted in one direction, something very like Perret’s island of 1911.
An affinity between Kilauea and Mauna Loa was obvious. In 1916 Mauna Loa completed its summit gushing by splitting open the mountain’s southwest rift and making a lava flow into ranch and forest lands of South Kona. But just as Mauna Loa activity ended, the entire Halemaumau bottom thirty miles away lowered dramatically during one day, leaving a deep seething puddle of melt, surrounded by roaring red hot avalanches. The coincidence, along with appropriate earthquakes, was unmistakable.
Immediately after the lowering, the liquid lava of Halemaumau welled up border wall cracks and cascaded through the talus to form an oval pool in the bottom funnel of broken rock. The lava column rose 600 feet in the next six months and a lobate lake developed, its coves separated by sectors of overflow lava which lifted slowly into crags in the center. In 1917 the lakes and crags inside Halemaumau were less than 100 feet down, the lake shores became accessible for experiments with iron pipes, and the crags came into view from the Observatory, fully justifying the daily photograph for comparing changes of the distant pit.
11. Lava lake, showing bench, March 30, 1917