The curve as a whole from 1823 to 1924 shows a notable crest from 1855 to 1890, and a crest of the greatest volume of Mauna Loa gushing occurred between 1855 and 1877. Stearns and Macdonald object to this diagram as not showing all the little intermediate events, but what I have taken are the actual peaks and depressions above sea level and those which correspond to the sunspot interval of 11.1 years. This is an average even for sunspots, which had long intervals at the beginning of the nineteenth century, a time when no reports were made for Kilauea. I have guessed a drop of Kilauea lava as dating from about A. D. 1800, corresponding to the notable expulsion of Mauna Loa lava through Hualalai, and an imaginary unreported lowering eleven years thereafter, as it is improbable the island was wholly dead in the first twenty years of the century. The explosive eruptions of 1790 certainly produced a big collapse at Kilauea. My faith in this diagram is based on the fact that our own eruption sinkings at eleven year intervals (1902, 1913, 1924, and 1935) agree so well with an eleven-year theory that we are justified in looking backward for eleven year averages. Perret has found intervals of about a decade for Vesuvius. All my experience of Hawaiian lava leads to the belief, shown by our lava tides and several short-term diagrams, that rhythmic periods of a volcanic system are related to gravitational control of the sun and moon. There are rhythmic controls of the globe by the gravitational control of the sun and moon. There are rhythmic controls of the globe by the sun, and rhythmic controls of very deep volcanic cracks by the globe, and rhythmic controls of individual groups of volcanoes by the long volcanic chains over cracks. Our experimental data are limited by the little groups of volcanoes, and so the big rhythmic movements seem inaccessible to science, mostly because we have no record of relationships of single volcanoes 500 miles apart in such a place as Alaska. We raise no question about night and day or about the oceanic tides or about the moon’s phases. We know there is a rock tide in the earth, that there is a hot earth core of about 2200° Centigrade which appears to seismology to be a very massive liquid 1,800 miles down. Gravitation is the controlling force of the solar system, the galaxy and the universe, and it works by rhythms, from the orbits of the planets in years, to the outermost spiral nebulae in millions of centuries. We are ourselves controlled by it in locomotion and in the circulation of the blood. Therefore to think of volcanoes as anything but periodic and gravitational in their relation to the globe would, to me, make the science of volcanoes entirely uninteresting. All science lives on rhythmic action.