PICKERING. LUNAR AND HAWAIIAN PHYSICAL FEATURES ( OMI'AKED. 157 
purely a cinder cone its angle might rise to 20° or even 30°. Etna and Manna L>a 
are both lava cones, the lava of the latter being more fusible. We may infer that the 
lunar cone is composed of similar material. It is probable that other similar la\ 
cones exist upon the Moon, and one is suspected lying six-tenths way from Copernicus 
to Kepler, and a little to the north. 
Lunar photographs are usually oriented with south at the t<>p. The right hand 
side is called east. Figures 14, 15, 31, and 35 were taken with a telescope of long 
focus, using an aperture of six inches, at the Harvard Station in the Island ot 
Jamaica. The remaining lunar photographs were copied from lantern slid s from 
photographs made by Professor Ritchey at the Yerkes Observatory. In Figure 5, one 
diameter to the south, and a little to the east of Bullialdus is a pair of coneless lava pits, 
the southwestern one being much the larger of the two. A few other very minute pits 
are shown upon the photograph, but all the larger ones have cones. In Figure 21), in 
the upper left-hand corner, five small craters are Bhown in a line running north and south. 
The northern one, which is also the sm 
One slightly larger 
g 
so coneless, is shown just above the centre of the picture, on the southern side of the 
•eat rill. It measures five miles in diameter. These seem to be true engulfment cra- 
rs, as distinguished from the expulsion craters hitherto described. Similar lava pits 
are found to the west and northwest of Copernicus, and also upon the Oceanus Pro- 
cellarum. In general they are very minute objects. No large crater pits are known. 
In Figure 7 we have a small terrestrial crater of this type. It is known as 
Kauhaku, and is found on the island of Molokai. It has no exterior cone whatever, 
and is merely a hole in the ground. Even explosive craters start in this form, the 
cone being formed immediately of materials ejected from the hole. Coneless engulf- 
ment craters abound on the slopes of Hualalai. See k, I, m, and/?, p. 171. Many 
are also found to the southeast and east of Kilauea, but the best known of all is 
Halemaumau, on the floor of Kilauea itself, d, p. 171. Figure 8 is known as Kuuohi, 
or more familiarly as the sixth crater, and is situated six miles to the southeast of 
Kilauea. See also/, p. 171. The floor of the main crater pit measures about 6,000 
feet in length by 2,000 in breadth. Its depth below the surrounding surface is 400 
feet. At its eastern end a second crater pit has formed. This measures 2,000 feet 
in diameter, and has an additional depth of 600 feet. It furnishes a vertical section, 
150 feet in depth of the primary floor, below which the walls form an inverted trun- 
cated cone to a small floor a few hundred feet in diameter. The lava of the upper 
twenty-five feet of the vertical section has a horizontal stratification, and is clearly 
distinguished from the portion below it. 
