causes that often arrest such an effect; but how few mines in the world are there that can produce any very great or productive mineral lodes above sea-level. Immediately the miner descends below sea-levels, if the lodes are mineralized at all, there they begin to concentrate their metallic compounds, each, as it were, by affinity to its own kind. The rationale, then, of all this apparent mystery is, that water is the prime mover, the great universal public carrier, never ceasing, never tiring through time.

We now come again to the Shelburne great north lode. The vein or leader of the lode, as well as the lode itself, is seen to be dry in its minerals. Once it was under water. The vein is full of blende. This mineral does not appear to be much affected by water, other than that it becomes deprived of its zinc and sulphur by exposure; the iron and arsenic remains, hence it is left in the lode in its original form. Blende in a lode, under water, is hard and compact; here it is quite friable and appears dried up. The lead in the lode is found in pockets and surrounded by this dry blende, and as the lode opens with the valley no water remains in it. A continual drainage is going on; therefore I infer that this is the cause of the general dryness of the lode. Had it been under water it would have been full of mineral, but they are now gone down to a lower level, and if ever the lode does make, it will be in depth; and that point is below the Androscoggin River. I do not think a fine lode like this can very well fail in becoming productive. It is a fine champion lode, and the bounding rocks are in such a position as to become regular feeders. Had there been a north and south lode, or cross course below, it probably would have been looking more kindly near the surface and carried more lead ore; but I find no trace of such at present. However opposite my views on these matters may appear with those given by the learned professors of geology, I do not know, but they present the only conclusion I can arrive at; if I am wrong, it must be attributed to my want of greater experience. I have nothing more than nature in her crude form for my guide. The south lode is more embedded in the midst of the mountain, and has a brook crossing it at right angles. There are also here some cross veins of trap forming little elvan dykes. This lode is much more likely to make ore above the valley than the others. It is also a long distance from the outcrop in the valley. Nevertheless, I have but very little opinion of its orebearing qualifications above water.

THE ADIT LEVEL.

This is driven westerly 75 feet on the course of the main lode, which is much more regular here in its stratification than at any other place. It is composed of opaque quartz with one vein more bright and congenial than the rest; it carries also a slight gozzan with spots of mundic; it is the most favorable looking part of the

lode at surface; it was under this that the shoot of silver lead ore was found to be going down when the mine was suspended by the original company, and it will be in this direction that the future main drivings must be directed.

THE STRATUM,

As described before, is mica, slate, granite, and gneiss. But before closing this part of the report, we must examine the rocks near the mine. We shall there find some very interesting phenomena. There is syenitic granite, gray granite, and quartzose rock, in masses embedded in the gneiss. There are also large masses of coarse granite lying on the mica slate. Who, then, can deny that micaceous rocks, even the schist, are not coeval with the granite? I am led to believe they are all of one common origin; that in the period and form of their crystallization, and in their chemical ingredients alone, they differ, and that there never was anything igneous in their construction.

About 300 yards below the mine is the mill-dam and the stamps, crushers, smelting furnace, &c. At this place it is very remarkable to see the gradual sinking of the rocks, even up to the very summit. As the soft micaceous rocks wear away in the valleys and brooks below, those above that repose on them follow down, leaving great open chasms in the rocks which are filled up with snow and ice, that, with the annual winter frosts, by expansion, are seen splitting their huge gray-capped heads into innumerable fragments. These accumulate until some monster rock of granite overbalances the mass of debris, when it sweeps down the mountain sides with an avalanche, filling the ravines and ledges below. There can be seen the slow but continual change that is taking place in the earth's surface; here can be seen the great northerly movement of the primitive formation, producing immense fissures and opening up new channels for the formation of lodes and cross courses which become the recipients of metallic minerals. These, again, become entombed by the onward moving masses: there they await, still growing, still concentrating, and still enriching, until the time shall arrive when they shall be wanted for the use of mankind. The contemplative mind untrammelled by the dogmas of sectarianism, and divested of abstruse speculative theories, may nere revel in delight. Here the visitor beholds the upheaving, the contortions and depressions of strata; here he may look with wonder, awe and admiration, on the sublime works of the Deity, and while he is astounded at the mighty effect, can, at the same time, behold the

cause.

PROGRESS OF EXPLORATION.

During my recent visit to Shelburne, time would not admit of my going over but a small section of this extensive property.

I have, however, carefully examined the strata for about three. miles up the brook that runs down the pass of Pea Mountain. I ascended as far as the top cliffs that stand beneath the summit house. It is very difficult and laborious travelling; there being no road near the river. The forest is quite primitive. Mr. Buxman, the surveyor of the estate, accompanied me. We ascended about 2000 feet, when our progress was somewhat hastily arrested by a heavy tempest of lightning, thunder, and a deluge of rain. I found no traces of any minerals besides iron. The rock formation is very interesting, particularly about this place, where the basins are some of them very large and deep. I have also been up the Peabody River as far as the Glen House. There are some few traces of mineral channels, but I think it is only iron. I ascended Mount Washington as far as the bald ridge, 4000 feet. This is a hornblendic slate formation, but very dry and barren. I collected some specimens of tourmaline and brown spar, but saw no traces of any thing like a lode. It was very foggy this day, June 15, and although the thermometer stood at 80 in the valley, at this height it was very cold. There were patches of snow in some places 8 to 12 feet deep. The rock formation is quite interesting. I am much inclined to think all the minerals lie on the Shelburne mine side of the river. There is a very large cross course or iron lode crossing the valley, and runs nearly under Mr. Burbank's house. In the second part of my report this will be described, as well as researches in Mount Hayes and the northern part of the set, with a valuation of the ship-building timber thereon; an estimate of the water power of the An. droscoggin River; suggestions for the building a manufacturing town; plans of the dam and weir head; estimate of cost in detail for working the north mine; also for working the south mine separately, with other information useful to the proprietors of the property.

ART. V.-THE PROPERTY OF THE PRIDEVALE IRON COMPANY.* BY PROF. WILLIAM B. ROGERS, STATE GEOLOGIST OF VIRGINIA.

THE 5TH, OR BIG COAL GROUP OF ORES.

The Fifth and last group of ores included in the Pridevale property, lies in the interval between the Two-and-a-half-feet Coal and the bottom of the Big Coal or Seven-feet vein. With the exception of bands situated near the bottom of the Big Coal, these ores are all limestone ores, or have been derived by oxidation from ores of that class.

The First of this group of ore beds has not yet been distinctly

[* Continued from page 370.]

recognized on the north-east, or Pridevale side of the river, but is well exposed on the opposite side, on the old Morgantown road, a few hundred feet beyond the lower ferry house. Its place is well marked by a coal seam of about twelve inches, lying above and separated from it by eighteen feet of yellowish and brown shales. This ore is a sandy argillaceous knotty rock, forming a bed of about twelve inches thickness, bluish within, but rapidly exfoliating in scales of brown oxide. In quality it much resembles the Snake-den ore, but it is more calcareous. Proof is yet wanting of its continuity over any considerable space. The same belt of shales, examined on a ridge about a quarter of a mile higher up the river, disclosed to me very little of the ore. Followed under deep cover, it cannot be expected to maintain its character; but from the absence of the oxide crust, will probably exhibit too large a proportion of the other ingredient.

This bed merits further search on both sides of the river. Its place in the limestone hill would be near its upper end, at some twenty feet above the Coke Railroad.

Contiguous to this coal seam, both above and beneath, a very meagre earthy ore is found, which has been mined at various points, in the hollow north of the Coke Yard. This is associated with calcareous shale and fire-clay, and consists of mere shells of ferruginous sand and clay, too poor in iron to be worth mining. I will therefore not enumerate this as one of the available ores.

At a level from twenty to thirty feet higher than the Small Coal already mentioned, and separated from it by shales, sandstone and a considerable bed of yellowish limestone, we meet with a very remarkable ore bed, which has thus far, however, proved too thin to be of much value. This is wrought by a drift on the eastern flank of the Big Coal hill. It is associated with calcareous shale and impure limestone ore, but the band itself is a very ponderous nodular ore, of a deep colcothar brown color, so rich and pure, that if reduced to powder, it would, no doubt, form a good pigment, similar to Spanish Brown. Its thickness, thus far, has not averaged more than two inches.

Above this level, the limestones and limestone shales which occupy a good part of the next one hundred feet of strata, present, where decomposed by exposure, shelly fragments of yellowish and brown earthy ore; but these being the product of purely surface action, give no true evidence of beds of ore. At a still higher level, within thirty feet of the bottom of the Big Coal, occurs another thin plate of coal, below which, in the fire-clay shales, we meet with irregular courses of limestone and of ore. These materials are exposed in numerous diggings near the crest of the limestone hill, and again on the road approaching the Big Coal. Some thin plates of rich carbonate have been found in the shales occupying this position, at one or two points in the

limestone hill; but here, and at the openings near the Big Coal, the ore is principally made up of concentric shells of earthy brown oxide, with large interspaces occupied by yellowish clay and sand. Where freed from the great excess of earthy matter, this ore will be found valuable for mixing with heavier and more refractory materials. A similar but richer ore, having the same geological position, has been opened by Moore on his own land, adjoining Hastie's on the opposite side of the Cheat. These ores being, I think, in great part the product of a decomposed ferruginous limestone and shale, lying near the surface, will become poorer and more calcareous when followed under a deep covering of rock; but in the localities mentioned, they range for a wide space near enough to the surface to retain their character of oxide ores.

I now come to the last belt of ores of this group: that included in the fire-clay and shales, extending below the Big Coal, through a depth of from twenty to twenty-five feet. This, at some localities, is a belt of great importance, as well from the persistency as the richness of the ore. At Oliphant's Furnace, north-east of the Anna, about seven miles, it consists of a finegrained, compact, rich nodular or plate carbonate of iron, from five to six inches thick, within a few feet of the bottom of the Big Coal. Similar plate and nodular ore has been mined beneath this coal, on the hill of the Eclipse Rock, below Pridevale. Under the mouth of the coal mine, two drifts have been carried for a short distance into the shales under the Big Coal in search of ore. The lower of these exposed a plate of very rich blue carbonate or Oliphant ore, but too thin to encourage further pursuit. In the upper drift, the roof of which is a foot or two below the bottom of the Big Coal, the light bluish argillaceous shales include several scattered courses of small nodules, and one course of large suggans, all of a bluish-white color, and rich in carbonate of iron. Near the coal openings, these shales have, by strippings, furnished a large proportion of similar ore; and at the mouth of the coal mine, a ditch, recently dug for the purpose of draining the works, in penetrating the fire-clay shales for some three or four feet below the coal, has disclosed the same nodules and suggans. Judging from the amount of ore seen at these openings, I would estimate the contents of the fire-clay shales, in a depth of six feet, in this particular locality, as equivalent to a plate of ore of about eight inches.

On the neighboring coal hill, a distance of about fifteen feet below the coal, benchings are now in progress which furnish a coarser ore of the same description, which, from the name of the operator, may be designated as the Collins Ore. These openings display scattered nodules of heavy blue ore, forming from three to five courses in a thickness of five feet of soft, crumbling shale, and beneath these a mass of flaggy ore, in thick plates separating,