OF THE HAWAIIAN ISLANDS. 381 



led for some distance, and we galloped over the hard gravel beds, dodging in a zigzag course 

 the clumps of bushes in our way. The morning was clear, and the birds which are scarce 

 near the shore, were abundant, and sang merrily. The path ended after three miles, and 

 we had to slowly pick our way over difficult and even dangerous lava-fields. Our horses 

 occasionally broke through, causing some trepidation to the riders, but no accidents occurred; 

 and after passing nearly round the summit, crossing the flow of 1801, and counting ten 

 flows from the top, and many others almost indistinguishable, we reached the base of the 

 highest plateau at eight o'clock, and left our horses in a little valley where strawberries were 

 abundant, and also American potatoes, planted by some native. 



A climb up a steep slope some three hundred feet high, and we were in the midst of a 

 series of large pit craters extending over the whole summit. These craters were very much 

 alike, from three to five hundred feet deep, and from seven hundred to a thousand feet in 

 diameter. The walls were of the solid graystone, seldom capped by cellular basalt in beds, 

 (although the lava was piled in scoriee near by), and were nearly perpendicular. Vegetation 

 extended to the bottom, and the beautiful Silver-sword [Argi/roxiphiiuu Sandvicense) was 

 growing in the clefts far down the sides. The bottom was usually flat and gravelly, but in 

 some cases covered with smooth black lava, and in others rough and broken. Fragments of 

 the walls were often seen at their base, and in one crater they were half melted into the 

 lava which covered the bottom, proving that the clinkstone of these mountain summits is 

 fusible by the melted black basalt. 



No signs of steam or sulphurous vapors were visible, but on the edge of one of the deep- 

 est craters, on the wall which separated it from another less than two hundred feet distant, 

 was a mound of scorice some fifty feet high, composed of drops and slightly agglutinated 

 fragments of lava of all sizes and colors, black, red, orange, blue, golden, apparently ejected 

 in a viscid state, and in the centre of this a blow-hole about twenty-five feet in diameter, 

 and, as nearly as we could judge by throwing stones, eighteen hundred feet deep to a ledge, 

 to one side of which we could see a deeper black hole. I was obliged to lie flat on the edge 

 to examine it, the scorioa were so loose, and the whole cone jarred as we climbed over it. 

 The inside of the blow-hole was of a brown color, smooth as if turned, and grooved horizon- 

 tally. No vertical striae could be distinguished, but as these horizontal grooves seem to 

 correspond to the strata of the adjoining crater-walls, I suppose that the projecting ridges 

 mark the more solid substance of these strata, which would be in their centre, while the 

 scoriae which separate the beds to some extent, would permit the deeper action of the 

 vapors which have formed the hole. Mr. Mann suggests that the column of ascending 

 vapors had a rotatory motion around a vertical axis, but in that case the grooves would be 

 spiral and not circular, and the fragments of lava ejected would have struck the surface 

 obliquely, unless thrown to such a height as to lose the original motion. The wearing force 

 must have been chemical rather than mechanical, as the wall of the crater adjoining, which 

 is not more than twenty-five or thirty feet thick, would have given way to any violent 

 explosion. A similar blow-hole was described by Ellis lower down the mountain. He 

 ascended Hualalai in 1823, and found on the side of the mountain a large extinguished 

 crater, about a mile in circumference and apparently four hundred feet deep. The sides 

 were regularly sloped, and at the bottom was a small mound with an aperture in its top. 

 By the side of this large crater, divided from it by a narrow ridge of volcanic rock, was 

 another, fifty-six feet in circumference, from which volumes of sulphurous smoke and vapor 



MEMOIUS BOST. SOC. NAT. HIST. Vol. I. Pt. 3. 97 



