Henry Woodward — On Volcanos. 343 



points volumes of vapour burst uj)wards with jets of highly viscous 

 matter, which, on cooKng, take the form of vitreous filaments or 

 scoriEe, (See woodcut. Fig. 5, page 342.) 



This is a flanking-crater to the old volcanic cone of Mauna-Loa. 

 It is 4000 feet above the sea, and about four or five miles in its 

 longest diameter. The whole mass is never agitated, save before a 

 discharge of lava, which rises from a vent eight miles east of the 

 great basin, and descends in a rapid manner for 4000 feet to the sea. 

 In 1840 it flowed at the rate sometimes of five miles per hour ! The 

 ordinary rate is less than half a mile. 



It boils up in this enormous cauldron-like lake often 15 feet above 

 the rim and cascades over in places ; but being very viscid, this 

 seldom occurs. Pools and lakes of fluid lava cover the surface, and 

 craterets 30 or 40 feet high also are seen emitting vapours and lava. 

 The date of the last eruption was 1868. 



In visiting Kilauea in 1864, Mr. T. Brigham writes : — ^ 



"As soon as our men came up with the blankets, we engaged 

 guides, and went down into the crater. The descent was steep and 

 winding, and we passed over several terraces, which were the result 

 of a sinking or falling in, as they were inclined and much broken, 

 and came under the grand pali of compact lava. A descent of more 

 than 400 feet brought us to the bottom, and we stepped from a 

 gravelly shelving bank on to a black lava which had broken out last 

 year under the north bank, and overflowed this end of the crater. 

 Where it touched the gravel bank it had glued to its under surface 

 the small fragments of stone, but had not altered their appearance, 

 and all along the edge it was cracked and laid up on the bank as if, 

 on cooling, the lava had fallen about a foot. The surface was covered 

 with a thin scaly vitreous crust, which crumbled beneath the tread, 

 sounding like snow on a cold morning, and thus a very distinct path 

 was made to Halemaumau, the enduring house of the goddess Pele. 



" The lava beneath this crust, however, was so hard as to give out 

 abundant sparks as the nails in my shoes scratched upon it. When 

 hard it was often iridescent, like some anthracite coal, and so closely 

 resembling this mineral that the difference would hardly be detected 

 by a cursory examination. The fresh lava exactly resembled that 

 from Mauna-Loa in the flow of 1859. 



"Three-quarters of a mile over this tmeven lava, and we came to 

 a long wall composed of fragments of all sizes and shapes, very 

 solid and heavy, and full of small grains of olivine ; and this wall, 

 which is concentric with the main wall of Kilauea, is said to rise 

 and fall, and sometimes disappear, which seems to be a fact, although 

 no one has ever seen it in motion. It is the fragments broken from 

 the edge of the crater by an eruption, and floated out to their present 

 position. An unpractised eye would see no marks of fire on the 

 rough, granite-like masses. 



"Caves, cracks, and ridges make the surface very uneven, and 

 after walking two miles we came to several large cracks of great 

 depth, but not more than a yard wide, and then a wall inclosing an 

 amphitheatre, down which we climbed on the loose slabs of lava. 

 1 Boston Academy of Natural Sciences, U.S. America. 



