A. EARTHQUAKES IN HAWAII.
Hawaii is regarded as a land where earthquakes are frequent and powerful. Since the invention of apparatus fitted to record the presence of these shocks, and the attention paid to their study in Japan, and under the auspices of the British Association For the Advancement of Science, so great has been the advance in our knowledge of these phenomena, that it is just to speak of the "New Seismology" : whatever had been written more than twenty years ago is of slight consequence in the comparison. Under the direction of Professor Milne sixteen seismological sta tions have been equipped with seismographs at as many important localities all over the world, and the reports from them studied and collated at the Isle of Wight in England. One of these in struments has been established at Sisal, near Ewa, on Oahu. Little has been reported from this station to the public, save that it served to allay apprehension at the time of the great earth quake in 1906 in San Francisco. There is a crying need for the establishment of a Seismological Observatory near Kilauea, simi lar to the analogous institution upon Vesuvius, where the phe nomena connected with the volcano can be observed, as well as those relating to earthquakes generally. The director of the Vesuvian Observatory has been able to send out authoritative warnings of disaster, which have been utilized by the public like the storm predictions from the National Weather Bureau at Washington. The Hawaiian volcanoes are fortunately situated at a considerable distance from settlements, and people congre gate to witness eruptions rather than flee from them ; but there is no part of the United States where the study of volcanic and seismic phenomena can be better prosecuted.
In the history of our volcanoes attention has been called to the occurrence of earthquakes, just as visitors happened to have noted them. A better record has been kept at Hilo by Mrs. Sarah J. Lyman, extracts from which have been published from time to time. Although ascribed to the Rev. D. B. Lyman, the first one of them is that published by Captain Wilkes in his Narrative, stat ing what the disturbances were between 1833 and 1841. After that time the same lady continued her record down to the end of 1885, when her life was ended. The family maintained the record
several years longer.
Three classes of seismic disturbances have been observed in Hawaii ; first, those connected with the volcanoes ; second, those that have been propagated by stresses in the earth away from the islands, sometimes called tectonic; third, the sea waves, where the jar has been communicated to the water of the ocean. Those of the second class are of less account locally than the others. It is important that they should be recorded by the seismographs and correlated with the same shocks in other lands. The inhabi tants of the Territory need not be apprehensive of any seismic dis aster, except those who live near the volcanoes of Mauna Loa and Kilauea, or in the path of the sea waves.
Of the volcanic quakes, that of i868, centering in Kau, is the most important. It is esteemed as one of the most forcible series of shocks connected with a volcano ever described. The state ments respecting these disturbances given in our account of the eruption of Mauna Loa in i868 will recall their terrible nature., All edifices, the trees ,animals and men were affected ; and sea waves were started at the coast. Many lives were lost. No ob servers in that day attempted to determine the various elements of the quake; but its connection with an eruption from Mauna Loa is now universally conceded. As in the fable, it may be said that the mountain was groaning to be delivered, and the birth was the deluge of lava shot up high into the air and flowing to the sea. By this occurrence it was evident that some of the erup tions from Mauna Loa were not of the quiet sort. Nineteen years later another eruption from near by was preceded by earthquakes numerous and violent, and still a third in 1907. And attention has been called to many other similar eruptions coming from the bases of both Mauna Loa and Kilauea in prehistoric times, which may have been equally violent.
When the records of the seismograph at Sisal are published, it will be possible to learn how important the tectonic quakes have been in our archipelago. So far as known, none of this class of shocks have been particularly severe.
Quite a number of the sea waves have made themselves felt among the islands, and attention will be called to a few of them.