■ GEOLOGY AND TOPOGRAPHY OF HAWAII. 163 



As usual, the first intimation of activity was given by the Jurid glare over the 

 summit crater. On January 9th slight earthquakes were felt on Hawaii, and 

 on the night of Januai-y 10th, 1907, Manna Loa was crowned with a bright 

 light. A few hours later the molten flood broke through the walls of the great 

 mountain on the southerly or Kahuku side of the dome, at a place 8,500 feet 

 above the sea and at a point about one half the distance from the sea to the 

 summit of the mountain. The flow in its course down the mountain passed 

 near the path of the 1887 flow. About the middle of its course the stream 

 divided into two main divisions, with smaller branches to right and left. The 

 tw'o main branches crossed the government road five miles apart on the night 

 of January 13th, i. e., within three days from the time of the outbreak. Neither 

 of the streams in their divided and weakened condition had force enough to 

 reach the sea. Both came finally to a halt on January 24th, about four miles 

 from the shore and within ten days from the time the flow broke out on the 

 mountain side. It has been estimated that in the upper part of the stream the 

 lava flood advanced at the rate of seven miles an hour, but lower down its ad- 

 vance was slow and majestic. Several hundred people from the vicinity and 

 from the other islands of the group rushed to the scene and were favored with 

 a splendid view of nature's most awe-inspiring spectacle. 



On November 25, 1914, white fumes were seen rising above the crater on the 

 summit of Mauna Loa. By evening the fume columns were seen to rise to a 

 height of 6,000 feet or more above the mountain, and, illuminated by the light 

 from below, presented a spectacle of splendid magnitude and beauty. It was 

 generally thought that this manifestation was the percursor of the usual type of 

 outbreak and flow, but this event did not transpire. After a short period of vary- 

 ing activity, confined entirely to the crater of IMokuaweoweo, the outbreak sub- 

 sided until no activity was visible from the observatory at Kilauea. 



Lava Discharged in the 1907 Flow. 



;\Ir. E. D. Baldwin has estimated that the flow of 1907 covered nine hun- 

 dred acres of rough land and that a volume of two hundred million cubic 

 yards of basaltic material was poured out. The flow of 1855 covered 15,000 

 acres and represented a discharge of six hundred million cubic yards of basalt. 

 The flow of 1880-81 covered 20,000 acres and equalled at least five hundred and 

 forty million cubic yards of lava. These estimates are jieeessarily suggestive 

 rather than accurate. When we look at the mountain as a whole we see numer- 

 ous streams of similar proportions showing plainly on its surface. Looking 

 deeper we find it made up of countless thousands of similar streams and con- 

 elude that at the present rate of growth millions of years have elapsed since 

 the building of the mountain first began. 



W\iRK OF Hawaii 's Volcanoes. 



It should be observed that during the period of more than one hundred 

 rears that ]\launa Loa and the volcanoes of Hawaii have been under observation 



