Mauna Loa soars 13,675 feet. Its snowy dome shares with Mauna Kea, which rises even higher, the summit honors of the islands. From Hilo, the principal port of the island of Hawaii, Mauna Loa suggests the back of a leviathan, its body hidden in the mists. The way up, through forests of ancient mahogany and tangles of giant tree-fern, then up many miles of lava slopes, is one of the inspiring tours in the mountain world. The summit crater, Mokuaweoweo, three-quarters of a mile long by a quarter mile wide, is as spectacular in action as that of Kilauea. This enormous volcanic mass has grown of its own output in comparatively a short time. For many decades it has been extraordinarily frequent in eruption. Every five or ten years it gets into action with violence, sometimes at the summit, oftener of recent years since the central vent has lengthened, at weakened places on its sides. Few volcanoes have been so regularly and systematically studied. KILAUEA The most spectacular exhibit of the Hawaii National Park is the lake of fire in the crater of Kilauea. Kilauea is unusual among volcanoes. It follows few of the popular conceptions. Older than the towering Mauna Loa, its height is only four thousand feet. Its lavas have found vents through its flanks, which they have broadened and flattened. Doubtless its own lavas have helped Mauna Loa's to merge the two mountains into one. It is no longer explosive like the usual volcano; since 1790, when it destroyed a native army, it has ejected neither rocks nor ashes. Its crater is no longer definitely bowl-shaped. From the middle of a broad flat plain, which really is what is left of the ancient great crater, drops a pit with vertical sides within which boil its lavas. [Illustration: _From a photograph copyright by E.M. Newman_ THE KILAUEA PIT OF FIRE, HAWAII NATIONAL PARK Photographed at night by the light of its flaming lava] [Illustration: _From a photograph copyright by Newman Travel Talks and Brown and Dawson_ WITHIN THE CRATER OF KILAUEA] The pit, the lake of fire, is Halemaumau, commonly translated "The House of Everlasting Fire"; the correct translation is "The House of the Maumau Fern," whose leaf is twisted and contorted like some forms of lava. Two miles and a little more from Halemaumau, on a part of the ancient crater wall, stands the Hawaiian Volcano Observatory, which is under the control of the Massachusetts Institute of Technology. The observatory was built for the special purpose of studying the pit of fire, the risings and fallings of whose lavas bear a relationship toward the volcanism of Mauna Loa which is scientifically important, but which we need not discuss here.