THE NEW-YORK EXHIBITION ILLUSTRATED.
plored to a less extent than the “ Wheatley,” both in depth and horizontal reach,but the results are every way encouraging. The mineral contents of the vein, itsgozzans, and its bounding walls, make it a counterpart of its more eastern neighbor.About 1700 feet of its horizontal range, and 180 feet in depth have been explored,
und the main shaft is being sank with activity.
The accompanying figure is a proportional sketch of a condensing engine of 24-inch cylinder which has been erected over the Charleston Mine. This is what inCornwallis called a “ "Whim Engine ” (i. e. an engine for moving the “ whim,”°r apparatus by which ore and rubbish is raised from a mine). In a more ad-vanced stage of explorations, a pnmping engine will be added, and then the pre-sent machine, which now does all the work, will be restricted to its appropriatefunction.
the agriculturist ? ” The whole world has been searched during the past ten years fornew sources of supply for this indispensable ingredient of all fertile soils. Is itnot possible that this maybe a new source, or one hitherto overlooked?
It is proper to advert before closing this article, to a few facts upon the gen-eral geology of this district, and of its metallic deposits which are of equal practicaland scientific interest. We will endeavor to make these statements as simple anduntechnical as possible. In the previous part of this article, it was stated that themineral veins of this district passed uninterruptedly out of the gneissic strata(rocks belonging to the granitic family) into the red sandstone, adjacent. Now itis a curious fact, worthy of much attention, that the metalliferous veins, so longas they remain in the gniessic rocks are lead-bearing veins; that as soon as thesesame veins pass the boundary of the primary and enter the red shales, the char-
BXPLOEIxa mGH-BEES8UEB.EBO.NB: AND 30II.EE, CAPABLE OP LOCOMOTK*.
Ix-beIt is
The above figure represents a very convenient and economical form ofploring Engine.” which has proved of great service where explorations were w 1Uiade prior to the erection of more expensive and permanent machinery.. Iteasily transported from place to place by horse power, and will serve to drain and
s *nk a shaft from 70 to 100 feet in depth.
The following tabular statement will show the duty of the several engines just
’ ’• i --- U „flM!
Namesof Mines.
Diameterof Cylinder.
Lengthof Stroke.
Load in lbs.
Gallons ofwater liftedper min.
Cwt of Coal
consumedper 24 hours.
Millions
lbs. lifted on©foot highper cwt. coals.
Wheatley
Mine.
Inch,
24
Strokesper. min.
10
Feet.
6
8360
360
2300
31.4
Brookdale
Mine.
24
6
8
4410
216
1500
16.2
Charleston
Mine.
24
6
5
6490
216
1200
28.
120
50
Aiiis duty is very much below tnat 01 me vuimw — 0
of which raise for every bushel of coal consumed, one million of pounds one foot
h’gh in a minute.
The depth of the several shafts, at these mines, on the first of July, was as follows :
The Wheatley, -. 240 fe ® fc
“ Brookdale, - . 428
“ Charleston,.
3 do. do. each, *
Besides 1 of 60, 1 of 90, and 1 of 100 each.
The total length of adit levels driven in these mines, up to the same date, was85 19 feet. About 1000 tons of lead have been raised and sent to market duringfte explorations, which the owners regard as only preliminary to the more vig-orous and productive workings of the mines.
As already remarked, the more easily volatilized of the lead ores, and t loseresulting as secondary products from the decomposition of galena by atmosphericpauses, occupy the upper and less productive portions of the veins. It is remarkable‘ h at among these the phosphate of lead should occupy so prominent a place—form-as n °t less than three-fourths of the whole metallic product of the upper levels.
4 r® a curious subject of scientific inquiry, from whence came such enormous quan-tities of phosphoric acid ? But a question of much more practical and economicalruterest is—“ Cannot the process of smelting these ores be so modified, that thePhosphoric acid may be secured in a form of combination fit for the purposes of
acter of their metallic contents is changed, and they become copper-bearing lodes.This general statement is subject to some exceptions, but it is, at the same timesupported by so many remarkable confirmatory instances, that there can be littlehesitation in accepting it as the law of the district.
The question of the geological age of metallic deposits has always been con-sidered one of the greatest practical and scientific importance. The Perkiomendistrict furnishes us some facts of singular interest bearing upon this question.The red sandstone deposits, into which the metallic veins have been intrudedfrom the underlying primary rocks, belong to the period known to Europeangeologists as the triassic, but more familiar as the new red sandstone, a depositmore recent than the coal measures. Now it happens that this quarter of Penn-sylvania is intersected by numerous veins of igneous origin, familiarly known bythe name of trap dykes:—it is obvious, on reflection, that inasmuch as these trapdykes intersect alike the primary and secondary rocks, that the fissures which theyfill must have been formed subsequent to the laying down of the sedimentarystrata, in other words, the instrusive rocks are more recent in their geological agethan the new red sandstone. The bearing of these facts upon the subject underconsideration will be understood, when it is known that in the exploration of theWheatley lode, three of these trap dykes have been discovered, intersected anddisplaced by the metallic vein. Moreover, such was the force producing the fissuresnow filled by the metallic lode, that the corresponding or opposite parts of the twowalls, have been heaved or displaced horizontally, in one instance more than fifty-sixfeet out of their original position.
These facts show not only that these metallic veins are more recent in theirorigin than the sedimentary deposits through which they are injected, but alsomore recent than the system of intrusive rocks. The same system of new redsandstone rocks accompanied by the intrusive trap dykes, is common also in thevalley of the Connecticut, and in the State of New Jersey. In both of theseplaces, indications of copper exist along the lines of junction of the severalmembers of the system, but they nowhere show a disposition to form well-de-fined courses of a metallic character.
It is the opinion of Prof. Eogers, that the metallic vein-fissures of this regionwere formed and filled during the long period when the eastern slope of theAlleghanies was still beneath the ocean, from whose waters were deposited theextensive belt of tertiary and cretaceous strata bordering the Atlantic border ofNorth America. The effect of the oceanic overflow appears in the very extensiveand deeply penetrating decomposition which the gneissic strata of this region havesuffered, yielding to the landscape those soft and beautiful swells and outlines forwhich this fine agricultural district is remarkable.
We would refer those who desire more particular information on this subject,
to the reports of Prof. Eogers already so often alluded to.
59