242 HAWATIAN ISLANDS. 
Hill; they extended either side to a distance of half a mile to a mile, 
and the surface consists mostly of loose blocks of the black rock, with a 
little reddish earth between them. The interior of the crater is covered 
with similar blocks and fragments of lava, with much scoria. ‘The 
scoria is very cellular, and occurs in twisted pieces of brownish-red 
and purplish shades. 
There is stil] another cone in this Diamond Hill region, standing at 
the foot of the mountain declivities, nearly in a continuous line with 
the preceding two. It isasmall and steep hill, about two hundred 
and fifty feet high, consisting wholly of blocks of black basaltic rock, 
one or more cubic feet in size. ‘The cone is broken down on the 
south side, and there are two rounded eminences on the north and 
northwest; and below these an uneven plain slopes away to the lower 
grounds around. ‘The tracts of lava blocks around this hill are con- 
tinuous with those of the crater just described, and extend westward 
about a mile. 
As Diamond Hill and these two craters are upon the same line, 
they may have originated in the opening of a single fissure, and have 
been cotemporaneous in their ejections. 
Punchbonl.—Punchbowl is much smaller than Diamond Hill, yet 
resembles it in general character. It has the same arid aspect and 
brownish tufa sides. The height of its summit above the sea is about 
five hundred feet, and the diameter at top not far from six hundred 
yards. The cavity of the crater is very shallow ; and the side to the 
south and southwest is about two hundred feet higher than the oppo- 
site. Nearly the whole cone consists of thin layers of tufa, which, as 
in Diamond Hill, lap over the rim of the crater, and slope both inward 
towards the centre, and outward to the plain around. 
The tufa is very neatly laminated, and seams and incrustations of 
carbonate of lime whiten it in all parts of the crater, having the chalky 
appearance already described. The dip inward and outward is about 
thirty degrees. 
This crater does not consist solely of tufa. Ascending from Hono- 
lulu towards the fortress at top, we passed over two dikes of basaltic 
lava intersecting the tufa, which are respectively three and twelve feet 
wide. ‘They appear in sight for a few rods only, and the tufaon each 
side is hardened and fissured parallel with the walls. The rock is a 
dark gray basalt containing some grains of chrysolite and a few par- 
ticles of augite; that of the smaller is compact, excepting the centre 
which is cellular for about a foot in width. 
