478 Correspondence. 
in the Vale of Clwyd, which has been singled out as an illustration 
of former denuding power, the edges of the Coal-measures (supposed 
to have been washed away) were observed cropping up on the 
western side of the vale, between the Limestone and Sandstone, 
when the Rhyl and Denbigh Railway was in course of construction ; 
and then the uppermost beds of the Carboniferous Limestone, as 
developed in North Wales, are seen in the immediate vicinity of 
Mr. Maw’s section; so that the supposed erosion could not have 
taken place. From the great similarity of the beds described by 
Mr. Maw as Permian, and those of the Millstone-grit near this town, 
I should not be surprised if the ‘Purple Shales and Sandstones’ of 
his section should be found to belong to that member of the Car- 
boniferous series; though, from one or more causes, but not neces- 
- sarily by Denudation or Erosion, they do not assume the massive 
proportions to which in other places they have attained. 
Apologising for the length of this communication, I am, yours 
truly, D. C. DAVIEs. 
Oswestry: Sept. 13, 1865. 
MISCELIANEOUS.- 
eee 
Sitver PEAK is believed to be as pre-eminent over all silver- 
mountains, as the Iron Mountain of Missouri is superior to all other 
iron-deposits. It is situated east of San Francisco, on the eastern 
side of the Sierra Nevada, and nearly one degree south of the city of 
Austin. It is some two miles from Castle Mount, an old extinct 
crater, about 5,000 ft. above sea-level. Near Silver Peak is an 
extensive deposit of salt, and not far distant a hill of pure sulphur. 
The whole country has a naked appearance, being quite destitute of 
vegetation, and bristles with mountains scattered over a plain of 
great extent. ‘The dreaded ‘Valley of Death, upon the plains of 
which, along the ‘old Spanish trail,’ travellers have suffered so much, 
lies but a short distance to the south-east of the crater of Silver 
Peak. Little Salt Lake, in Southern Utah, lies directly east of 
Silver Peak. At first the searchers after deposits of the precious | 
metals confined themselves to the Pacific side of the Sierra Nevada; 
but discoveries in New Mexico, Arizona, and Virginia city induced 
a thorough examination of the east side of that range. This proved 
a great success, the most brilliant result of which is found in the 
neighbourhood of Austin, on the line of the great overland mail, 
where a city has sprung up within three years which, Senator Nye 
says, contains a population of 10,000. From along this line of ex- 
ploration the miners are rapidly extending their operations, both 
north and south. Recently (within six months) they came upon 
this immense deposit near Castle Mount. Twelve exceedingly rich 
lodes, or ‘ledges’ as the miners call them, were discovered on that 
single mountain. This is believed to be the most valuable discovery 
yet developed. The specimens—a great number of which have 
been brought to New York by Colonel Catherwood—are certainly 
very remarkable, and are well worthy of attention. If there is no 
