Then W. H. Hammond, physicist in charge of a testing laboratory at Pearl Harbor, suggested that I revive my 1897–1908 testing of steel for abrasion hardness, later continued by Boynton, for his laboratory of the Navy. Thus I started hardness testing at the University and carried it on for ten years. I used diamond and other abrasives in instruments to show directly on a dial the rate of wear of metals or minerals under standardized conditions, with a constant and reproducible motor tool. Abrasion hardness turned out to be as tricky a problem as my range finders and shock recorders. This activity brought together in the University laboratory and in the laboratory at Hawaii National Park many records, manuscripts, and specimens. Ruth Baker, who succeeded Sato as secretary, did valiant work sorting out materials from many expeditions which had been dumped in disorder because of war and fire at the Kilauea Observatory. Though the Park had built a new house for naturalists, and for the seismographs, shops, and records, it was taken over by the Commanding General on Hawaii, imposing considerable hardship on Finch and his assistants. One assistant was Burton Loucks, instrument maker, who married Miss Baker. Another, Austin Jones the seismologist, was transferred to care for seismographs set up to measure faulting and tilt around Boulder Dam. Dr. Howard Powers, after work for the Geological Survey and the Territory on the island of Maui, joined Jones eventually to enter into a new section of volcanology, established in Denver under the Geological Survey, especially to assist the Army and Navy studies of Aleutian volcanic eruptions, wherefrom harbors and airfields were sometimes endangered. [Illustration: _27. Fountain in Halemaumau lava lake, May 23, 1917_] [Illustration: _28. Rare dome fountain during eruption of Kilauea Crater, March 20, 1921_] [Illustration: _29. Lava stream issuing from a spatter cone near rim of Halemaumau, February 9, 1921_] Three events of volcanic and seismic importance to Hawaii during the 1940’s were the eruptions of Mauna Loa in 1940 and 1942 and the 1946 tidal wave caused by a submarine earthquake south of Unalaska. The wave engulfed the wharves and shorefronts of Hilo and eastern Maui and caused considerable damage elsewhere. We were familiar with the recording by our seismographs of earthquake centers under the sea of Alaska and Japan, and with the interval of hours that followed before dangerous water waves reached Hawaiian shores. We had also had a bad tidal wave in Kona, originating off Japan; and two or three such waves which damaged Kahului and Hilo had originated in big submarine earthquakes off the Alaskan Peninsula. The Japanese fishermen, from our published warnings, always took their sampans to deep water, and the Navy had instructed me to let them know right away if the seismographs recorded a distant earthquake capable of making a tidal wave.