416 APPENDIX. 
The great distance of the Pahoa well from the coast is a reason for the 
small amount of coral rock. 
b] 
The water of Campbell’s well was “as salt as brine ;” it stood in the 
casing about a foot higher than the water of a surface well adjoining. 
The artesian wells indicate great diversity in the thickness of the coral 
formation, and a dependence, as regards thickness, on distance from the hills. 
Campbell’s well, No. 15, is about 4,000 yards from the hills, and has a lime- 
stone bed of “hard coral rock, like marble” over 500 feet thick, which at 
bottom is 865 feet below the sea-level, besides a bed of probably similar origin 
over 200 feet lower; while King’s well, about one half nearer the hills has the 
bottom of the lowest coral bed at 700 feet. ‘The same level in Goo Kim’s 
well, No. 13, is at 430 feet, and in the Pahoa well, No. 12, still nearer the 
hills (the distance but 1,500 feet), 275 feet. All these levels are below the 
limit of growing corals, and far below the Hawaiian limit, which, according 
to Mr. Agassiz, is less than 100 feet. But the intercalation of beds of lava, 
tufa, and clay (either tufa beds or decomposed lava) make a close comparison 
of the sections in this respect with one another impracticable. 
The wells about Punchbowl have great interest. The Foster and Palace 
wells, Nos. 1 and 2, are about 600 yards from the base of Punchbowl, and 
bear N. 70° W., and S. 65° W., from its centre. In each, the bottom bed of 
coral extends to a depth of about 450 feet (450 in No. 1, and 452 in No. 2), 
which, as No. 2 shows, is 442 feet below the top of the elevated fringing reef. 
Hence, in the case of each, the coral reef rock at bottom is more than 350 
feet below the Hawaiian limit of growing corals. Difference in position must 
account for the difference in the upper portion of the two sections; and the 
chief fact as to position is that the Foster well is within the Nuuanu Valley, 
where clay and bowlders may have been carried down by its running waters. 
But in an important feature they are alike, the coral bed just referred to hav- 
ing over it, in one, 300 feet of “clay,” and in the other, 278 feet. This thick 
bed of “clay ” was very probably made by cinder-ejections from Punchbowl; 
for the tufa of Punchbowl (a kind of palagonite), if brought up from a boring, 
would feel and look much like clay. This is further sustained by the fact that 
in the wells more to the south of Punchbowl, little of the clay-bed was found, 
the localities being too far to the eastward to receive much of the cinders; 
their bearings from the centre of Punchbowl are between S. 30° W., and 
Spiel De 
In each of the five wells, Nos. 3 to 7, the top layer consists of 12 to 16 
feet of soil and black sand. Below this, in Nos. 3 to 6, there are, severally, 
178, 200, 200, 204 feet of the coral limestone of the elevated fringing reef ; 
and the lower limits of the bottom layer of coral are, severally, at 515, 380, 
397, 393 feet. In the Wilcox well, No.7, a bed of lava, 40 feet thick (perhaps 
