United States or Singapore ? Vote for the TOP Country of the Week !
One of the most remarkable of these crateriform mountains is that named Copernicus, situated in a line with the southern prolongation of the Apennines. Of this mountain Sir R. Ball says: "It is particularly well known through Sir John Herschel's drawing, so beautifully reproduced in the many editions of the Outlines of Astronomy.
On its broad outer slope, near the summit, there is a fine crater, and S. of this running obliquely down the slope a distinct valley. On the N.E., where the glacis runs down to the level of the surrounding plain, there is a large crateriform object with a broken N. border, and a small crater opposite the opening.
Instead of being a regular, round-headed cone, like the Jebel el-Abyaz for instance, the summit was distinctly crateriform. The greater part of the day was spent in examining it, and the following are the results. This Jebel el-Maru showed, for the first time during the whole journey, signs of systematic and civilized work. In many parts the hill has become a mere shell.
This hill is conical, 450 feet in height, and retains some traces of having had a crateriform structure; it is composed chiefly of matter erupted posteriorly to the elevation of the great basaltic plain, but partly of lava of apparently submarine origin and of considerable antiquity.
On the N.W. is a remarkable crater-row, called, from its discoverer, "Webb's furrow," running from a point a little N. of a depression on the border to a larger crateriform depression on the S. of Hipparchus K. Birt terms it "a very fugitive and delicate lunar feature."
A more exuberant and rapidly growing form of epithelial cancer, described by Hutchinson as the crateriform ulcer, commences on the face as a small red pimple which rapidly develops into an elevated mass shaped like a bee-hive, and breaks down in the centre.
There are many others extending for some distance in the Eiffel chain and in the vicinity, but those I have mentioned are sufficient to guide the footsteps of the inquirer. The basin of the Lake of Laach is nearly circular and crateriform; it is a mile and a half long, and about a mile and a quarter in breadth.
The most remarkable feature in this crater is the great development of strata converging inwards, as in the last case, at a considerable inclination, and often deposited in irregular curved layers. The internal and external strata differ little in composition, and the former have evidently resulted from the wear and tear, and redeposition of the matter forming the external crateriform strata.
The lava is vesicular, but the vesicles never reach the surface of the branches, which are smooth and glossy. About a mile southward of Banks' Cove, there is a fine elliptic crater, about five hundred feet in depth, and three-quarters of a mile in diameter. Its bottom is occupied by a lake of brine, out of which some little crateriform hills of tuff rise.
There appears to me to be insuperable objections to this view: on the other hand, I can hardly believe, in this and in some other cases, that these marginal crateriform mountains are merely the basal remnants of immense volcanos, of which the summits either have been blown off, or swallowed up in subterranean abysses. From our elevated position we enjoyed an excellent view over the island.
Word Of The Day