The Way of a Lava Floiv. 



141 



On the twenty-nintli of Julj^, having in the meantime made the ascent of 

 Mauna Loa, I retnrned to Kilanea. In the afternoon I went to the Kan bank, and 

 while Mr. Furneanx sketched Kilanea from the west, I photographed the cliffs of 

 Halemanmau, and then descending two of the gravelly terraces which form the border 

 of the crater on this side, fonnd mj'self on the brink of a perpendicnlar cliff beneath 

 which the lava was escaping from several openings situated on the lower edge of the 

 dome. The action was curious, and although the heat was very great at this height 

 of nearly a hundred feet, I managed to watch and sketch it for nearly an hour. The 

 noise here was peculiar; for in addition to the clinking as of shivering glass, usually 

 heard when this black and glassy lava cools, there was a dull subterranean rumbling 

 as of heavy machinery moving beneath the crater. It was the same noise I had heard 



during an earthquake two days before at 

 Stone's ranch many miles from Kilauea, 

 and it was not unlike the sound of many 

 looms in a cotton factory. Here there was 

 no earthquake tremor, although there is 

 always in and about Kilauea a vibration of 

 the ground very clearly seen when using a 

 compass needle, but seldom noticed other- 

 wise. The cliff where I watched was not 

 over the lowest part of the crater, but was 

 where the active pools approached nearest 

 to the outer walls, for the dome has a v^ry excentric apex. The fluidity of the lava 

 as it came to the surface was about that of cream. There is, so far as I know, no 

 definite scale to which we may refer various degrees of viscidity, and I am compelled 

 to use homely comparisons, which have the further disadvantage of being a variable 

 standard. It was white-hot cream when it came out from under the crust, but in the 

 distance of perhaps a foot had changed to a cherry-red molasses, while a few feet more 

 transformed the stream into full red tar. By daylight the color ranges from that 

 of arterial to venous blood, and thence to a slaty blue, marking the loss of tempera- 

 ture by chromatic changes. At night all the moving portion is a bright red. A single 

 outlet of small dimensions made much noise blowing, although the gas expelled was 

 invisible. The lava (.\ in the diagram) issued white-hot, ran a few feet rapidl}', then 

 crusted over, retaining its red glow along the edges of the narrow conduit, c. At b there 

 was a contradlion and the flow stopped for a while ; then the fountain at A renewed the 

 supply and the lava ran rapidly from the narrow outlet B, spreading in a broad, thin 



sheet which did not lose its color until it reached the point E, while the original nar- 



[519] 



Fig. S3. I.AVA SPRING. 



