Characteristics of Volcanoes, with Contributions of Facts and Principles from the Hawaiian Islands

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1890 edition. Excerpt: ... I. THE ISLAND OF HAWAII. General Observations.--A map of Hawaii makes the frontispiece to the volume. The island is approximately triangular, with its greatest length from north to south about ninety-three miles, and the extreme width eighty miles. It lies mostly between the parallels of 19 and 20 20', and takes the trades on its northeast side. Many important facts may be read from the map at a glance. Among them the first to be noted is the simplicity of the topography and the gentleness of the mountain slopes; secondly, the situation of the five volcanic mountains; thirdly, the almost total absence of rivers, except on the north and northeast slopes, or the windward sides; and fourthly, the courses of the great lava-streams of the past sixty years, indicated by long dotted areas. The Kohala Range, on the north, is the remains of the oldest of the Hawaiian volcanoes. The slopes are deeply cut by valleys of denudation. Between it and Mount Kea lie the broad plains of Waimea, 2,500 to 3,000 feet above tide-level, made by the lavas of the base of Mount Kea. On the northeastward, the ocean side, there are the precipitous gorges of Waipio and Waimanu, 1,000 to 2,500 feet in depth, so profound and so bent around into parallelism with the coast that erosion cannot explain their origin. Mount Kea has long been extinct, probably for centuries, yet not long enough for denuding action from the abundant rains over the windward slopes to extend the torrent channels more than half-way to the summit. Mount Hualalai has been quiet since 1801, when the last eruption was witnessed by Turnbull. It is a question whether it did not reach final extinction as a consequence of that discharge. Its slopes so blend with those of Mount Loa that it is hard to tell where...