174 HAWATIAN ISLANDS. 
accommodated within its walls, or that the lofty dome of this cathedral 
would stand with its pinnacle but 120 feet above the black ledge. 
The great lake of boiling lava, 1000 feet by 1500, as above mentioned, 
is a small object in such an area. 
A better idea of the actual form of the pit will be obtained from a 
transverse section here represented. It is taken in the line of the 
VERTICAL SECTION OF KILAUEA. 
shorter diameter; a section through the longer diameter on the same 
scale (a third of an inch to a thousand feet) would not have room on 
the page; mm’ is the whole breadth of the crater; on, o' n’, the black 
ledge; pp’ the bottom of the lower pit; mp, m'p’ the walls of the lower 
pit, 342 feet in height; m 0, m’ o', the walls above the black ledge, 650 
feet in height. 
The walls of the crater (m 0) are vertical, or nearly so, through the 
most of their circuit. ‘There is a break with several fissures in the 
northeast corner, (fig. p. 173, the wpper side of which is north,) the 
usual place of descent; and on the southeast side (at c) there are two 
or three sloping declivities, on which one of the famous sulphur banks 
is situated. 
These bluff sides of the pit consist of naked rock in successive 
layers; and in the distance they look like cliffs of stratified limestone. 
The layers vary from a few inches to thirty feet in thickness, and are 
very nearly horizontal. They are much fissured and broken, and 
some have a distinctly columnar structure. Open spaces or caverns 
and ragged cavities often separate the adjacent layers, adding thus to 
the broken character of the surface, and at the same time giving 
greater distinctness to the stratification. ‘The black ledge varies in 
width from one to three thousand feet. With such dimensions, it is 
no unimportant feature in the crater. The lower pit is surrounded by 
vertical walls, (n p, n' p',) which have the same distinctly stratified 
character as those above, and are similar in other features. More 
numerous fissures intersect them, indicative of the unstable basis on 
which they rest. ‘The general form of these lower regions is much 
like that of the whole crater, though narrower, as the ledge is widest 
on the longer sides of the pit. ‘The whole length, as ascertained by 
the surveys, is about two and a quarter miles, and the breadth ave- 
