206 HAWATIAN ISLANDS. 
after show that Kilauea, in its great boiling pools, gives a more correct 
idea of the action of craters of ancient times than any of the volcanoes 
more frequently appealed to for illustrations of volcanic action. 
We leave Kilauea here, to resume again the subject of volcanoes 
after describing the other craters of the Hawaiian Group. 
b. Summit Crater of Mount Loa. 
In the extended area, very gently sloping around, which forms the 
summit of the rock-built dome Mount Loa, is the deep pit crater 
Mokua-weo-weo.* It has a somewhat elliptical figure, as shown in 
the annexed cut, with its diameters 
13,000 and 8,000 feet respectively, the. 
longer lying nearly in a north-by-west 
and south-by-east direction. But the 
deep part of the crater is nearly circular, 
and has the breadth of the smaller dia- 
meter; the northern and southern por- 
tions being shallow, and constituting, 
with reference to the central portion, a 
kind of terrace. The walls, through a 
considerable portion of their circuit, are 
abrupt or even vertical, and are strati- 
fied in structure like the sides of Ki- 
lauea; on the west side the height was 
found by Henry Eld, Jr., to be seven 
hundred and eighty-four feet, and on the 
east, four hundred and seventy feet. 
The bottom of the pit, when examined by Captain Wilkes and the 
officers of the Vincennes, consisted of solidified lava, through which 
there were several fissures and fumaroles emitting steam and sulphur 
vapours in large volumes. Some parts were rough with clinkers, 
while in others, smoother tracts of solid lava constituted the surface. 
The fissures had in general a north-northwest and south-southeast 
* The summit crater was examined and thoroughly explored by Captain Wilkes and 
the officers of the Vincennes, and a detailed account of it is given in the fourth volume of 
the Narrative of the Expedition. In the account presented, we have stated only the facts 
of special geological interest. 
The name of the crater is pronounced Mokooah-wayo-wayo. 
