DICKERING. — LUNAR AND HAWAIIAN PHYSICAL FEATURES COMPARED. lf*)9 
In drawing the sections on p. 171, it was necessary to represent them on several 
different scales. The smallest scale adopted was j-gfo-Q or a quarter of an inch to 
1000 feet. The dimensions of all save a, b, and d are based only on estimates, but 
these were made on the spot with all possible care, excepting c and e, where (lie 
estimates were based on photographs, and o, for which I had to depend on my 
memory. All the sketches were either made on the spot or were taken from 
photographs. The craters on Hualalai are designated for lack of a better system of 
nomenclature in the order in which we visited them from Iluehue. Number 8 is 
the summit crater. In the description which follows, the length of 1000 feet is 
given in each case in inches as measured on the section. 
a Tuff cone. Punch Bowl, ] inch. 
b Tuff cone. Diamond Head, \ inch, 
c Cinder cone on Manna Kea, 1 inch. 
d Lava pit. Kilauea, \ inch. 
e Lava cone in Haleakala, 1 inch. 
/ Lava pit. Kauohi or Sixth Crater near Kilauea, \ inch. 
g Lava cone and ring. Crater number 10 on Hualalai, 2 inches. 
h Lava ring. On floor of crater number 10 on Hualalai, 8 inches. 
i Lava ring on Mauna Loa, 2 inches. 
j Lava bowl. Crater number 9 on Hualalai, 1 inch. 
Jc Lava pit. Crater number 11 on Hualalai, 2 inches. 
I Lava pit. Crater number 3 on Hualalai, 2 inches, 
ra Lava pit. Crater number 6 on Hualalai, 2 inches. 
n Lava pit. Crater number 12 on Hualalai, 1 inch. 
o Lava pit. Alealea or Fourth Crater near Kilauea, \ inch. 
p Lava pit. Crater number 7 on Hualalai, 4 inches. 
After the craters, among the most important features of the lava flows are the 
elevated formations, — the spiracles, pinnacles, and ridges. When the gases work 
their way up to the surface from a subterranean cavity they escape by little 
apertures called blow holes. In so doing they often carry small quantities of 
lava along with them. This lava quickly hardens on reaching the surface and 
builds up a tube around the aperture which we have called a spiracle. Some- 
times it is closed at the top by the last escaping lava, and sometimes it is left 
open. These spiracles are found of all sizes, from one measuring three or four 
inches in diameter, up to another measuring one hundred feet. The former, found 
in Kilauea, was twelve inches in height, and contained a hole one inch in diameter 
running its whole length, except where it was closed at the top. The latter was found 
on Hualalai, and will be described presently. 
