ORDER OF EVENTS 493 



charge of streams of melted lava. The irregularities of the southern 

 edge of the cone from Kilauea to the South cape were produced at this 

 time. Mohokea was the most important of these displays. The three 

 intermontane valleys sank down in the usual style of the breaking of the 

 superior crust from a caldera. Perhaps, because of the great size of the 

 pit, all the fragments could not be absorbed by the inner fiery fluid ; two 

 rows of blocks were crowded up, and the work of fracture ceasing, the 

 great masses of rock were elevated and held in position. It is to be noted 

 that the faults are at right angles to those running seaward from the 

 apex of Mauna Loa. This agrees with the theory of W. L. Green, that 

 the discharges of the lava from the interior of the cone always take place 

 at the intersection of the cross-fissures. Very much lava flowed away at 

 this time, including the three valleys mentioned and the crust adjacent 

 as far as to Kapuna. 



3. Two great eruptions, separated by a long interval of time, threw 

 out into the atmosphere enormous clouds of ashes. The intermediate 

 period was long enough to allow of the invasion of plants over the sterile 

 area of silt. Because of the occurrence of this ash entirely around the 

 circumference of Mauna Loa, it seems most likely that the vent was at 

 Mokuaweoweo. A gigantic cloud of steam carrying dust ascended miles 

 into the air; the cloud rose above the trade winds and spread out on all 

 sides, while the particles too heavy to be carried great distances fell to 

 the ground. Three recent eruptions of a similar nature are on record — 

 from Krakatoa in 1883, from Tarawera in 1886, and during the present 

 year at Vesuvius. I have estimated that 2,000 square miles of the island 

 of Hawaii were covered by these ashes. These are preserved, but they 

 must have been strewn much beyond these limits and lost in the sea. 

 Could any one have observed the skies at this time he would have seen 

 repeated the sky glows, the Bishops rings, and the green sun. This must 

 have been an explosive eruption — a style of discharge denied to Hawaiian 

 volcanoes by the early writers. 



4. Several flows of Pahoehoe will be described presently overlying the 

 ash, some of them from the Mohokea depression itself. 



5. More or less connected with them are several discharges of aa. 



6. Last of all, I should not fail to recall the disastrous earthquakes of 

 1868, whose epicentrum lay in the vicinity of this caldera. No more 

 severe shocks have ever been experienced since the country has been set- 

 tled by people of European descent. The quakes were observed at Kona, 

 Kahuka, Waiohinu, Kau, Kilauea, and Hilo. All were severe, but the 

 greatest devastation was wrought in the vicinity of Mohokea. Can it be 

 that the seat of the seismic disturbances lay beneath Mohokea? The 



XLIV— Bull. Gbol. Soc. Am., Vol. 17, 1905 



