locks, very plainly, across the mountain from the Musconetcong to the Pequest, just south of Townsbury. It is then seen on the north. side of Jenny Jump Mountain, and again on the south side of the Pequest, near Butzville, and just north of the Presbyterian church. at Oxford. From there on to the Delaware it can be traced through Belvidere to the river's bank, just north of the Pequest.

In Pennsylvania it can be traced from the Delaware, just above Marshfield Station, on the Delaware, Lackawanna, and Western Railroad, along the south side of the valley of Jacobus Creek to the village of Johnsonville, and from there on to the Blue Mountain, which it meets about three miles northeast of the Wind Gap.

In New York the line crosses Staten Island near its southern end, and then along its southeastern border, near the Great Kills, to Fort Tomkins, at the Narrows. On Long Island the line begins below Fort Hamilton, and extends between Brooklyn and Flatbush, just north of Jamaica, and following the south border of the line of hills, which marks the north shore of Long Island, it finally crosses southeasterly, to the Atlantic shore, a little west of Southampton.

The accompanying map of New Jersey shows the part of that State which has been covered by the glacial drift. It also shows the irregular line of its southern edge, and that it recedes towards the north somewhat in proportion as the ground is higher above the sea-level.

To the north of this line the surface is mainly covered with heavy deposits of drift material, some of which have been brought from localities many miles distant. Where the rock-surface is not concealed by this coating of drift, it is hard and unproductive. The soils are much mixed, and the miscellaneous collection of boulders of granite, gneiss, conglomerate, limestone, quartz, iron ore, etc., leave one in doubt as to the source from which such dissimilar rocks could have come. Some expensive mine-workings have been undertaken in consequence of finding these erratic masses of iron ore.

To the south of this line the regular geological formations are much more thinly covered with the soil. There are some light banks of sand and fine gravel, but no masses of glacial earth and boulders, and generally the soil is derived from the underlying geological formations, and only changed by air, rain, drainage, vegetation, etc. The most remarkable difference, however, is in the rock-surface, which, to the south of this line, shows so much of the effects of disintegrating and decomposing agents. The granitic rocks are so de

composed, for many feet down, that they are cut as easily as earth. Good examples of this are seen in the excavations on the Pennsylvania Railroad about Philadelphia, and in those of the New Jersey Central Railroad from Clinton to Warren Junction. The limestones have been so much acted on by dissolving agents as to be thickly coated with earth, which is scarcely other than the impurities of the original stone.

And, generally, the conditions of the earthy and rock materials on the two sides of the line are such as would be expected if one had been left in quiet for untold ages, while the other had been subject to most powerful abrading and commingling agencies.

THE NEW WORKS AT CLAUSTHAL FOR DRESSING ORES. BY JOHN C. F. RANDOLPH, E. M., NEW YORK CITY.

(Read at the Amenia Meeting, October, 1877.)

THIS establishment being now in full working order, it has seemed of considerable professional interest to collect together, in a concise form, the various points as to its plan, method of dressing, and equipment. The data contained in this paper have been largely drawn from the able paper of E. Kutscher, constructing engineer of the works, contained in the Zeitschrift für Berg-Hütten-und Salinenwesen im Preussischen Staate, 1873, supplemented by some personal memoranda made while the works were under construction and by memoranda on the works appearing in various German technical papers from their completion up to date. This is probably the largest dressing works in the world devoted to the beneficiation of argentiferous lead ores, and it is doubtful if any establishment for the concentration of mineral of any description can compare with it in size. As showing the final practice adopted in an old and very conservative mining region, in which the concentration of ores has been a matter of constant practice and experiment for a very long period, these works are of peculiar interest. The fact that the Clausthal ores strongly resemble a very large and abundant class of ores found in the United States has always attracted the attention of American mining engineers and mine owners to the methods employed in dressing and smelting them. The study of their methods of concentration of ores has, however, always been full of difficulty,

on account of there having been in the Clausthal Revier no single large works carrying out a complete dressing of the ores and thoroughly equipped for the purpose. Until the erection of the new works, dressing was carried on in a large series of very small works, very imperfectly equipped, in which the concentration losses were very large. As a general rule these small works had grown up very gradually, and were filled with old and imperfect machines, which had been added at different periods, and were retained long after more perfect machines had been invented, because of the impossibility of replacing them without remodelling the works entirely. As in most cases this was impossible without digging new foundations, and erecting entirely new works, many of these Clausthal works presented in their equipment and appliances a perfect epitome of the history of ore-dressing from the earliest times to the present day. As museums they were interesting, but as dressing-works they were ill adapted to their work. Since the treatment in most of them was only partial it was continually a question if it would not be more economical to throw aside middling products from various operations than to transfer them to other works for further treatment. All of these old works depended entirely on water as a motive power, and in many of them several water-wheels of small power and awkward construction were necessary to accomplish the work even imperfectly. It was no uncommon thing to find water-wheels of small power and large diameters and but small head of water laboriously driving a single machine and not being thoroughly successful. Where heavy work like that of driving stamps had to be done, several water-wheels were sometimes made to combine their efforts. All of these small works were liable to a stoppage in ease of a drought. In the Pockthal and the Zellerfeldthal there were a large number of dressing-works of the character described. For a long time the desirability of continuous systematic dressing of the Clausthal ores was felt, and in 1862 it had become thoroughly evident that this would always be impossible with the existing works and that it would be equally impossible to remodel them so as to answer the increasing needs of the mines and furnaces. It was therefore decided to build one large works, compact and well equipped, in which the dressing should be both continuous and systematic, and to let this new establishment replace the old ones.

The site selected was the very advantageous slope of the Bremerhohe, facing the Pochthal, which was already occupied by the Clausthal Stamp Mills, numbers 1 to 10. The original plan con

templated a total capacity of 50,000 tons a year, driving the stamps at night, and the rest of the apparatus by day, and using as far as possible the existing water-power, but not being entirely dependent on it. Before the completion of this plan, it was modified to admit of a yearly capacity of 75,000 tons a year or 250 tons a day on the same basis. The increased production of the Clausthal mines in 1866 made a further change of plan necessary, and their final form is for a capacity of 150,000 tons a year or 500 tons per day if all the machinery is driven both day and night. In erecting the works some of the old buildings have been utilized, but most of the buildings are new, and very large. Some portions of the old equipment, also, have been retained as serviceable. The new works were completed in 1872, and probably cost more than the original estimates on account of the several changes in plan during construction. A very important consideration connected with the erection of the new works was the opportunity offered by their construction on the site selected for carrying out a broad and novel plan of transportation for the ores from Clausthal mines, drained by the celebrated Ernst August tunnel, which supply the larger part of the ore treated in the works. The Ernst August tunnel is a navigable adit, and strikes immediately beneath the hill ou which the works have been erected. The plan was to tap the adit by a shaft from the upper part of the slope, and thus render it possible to bring the ores by boat from the various mines through the adit and the shaft directly into the works. Other ores from the Silbersegen Mine to the south were to be brought through a level and a second shaft, and the small amounts of ore from the Altersegen Mine to the east were to be brought by tramway. The advantages and economy of such a system of transportation of ores to the works need hardly be dwelt on. In erecting the works advantage has been taken of the slope, in the usual way, so that the ore descends from treatment in one building to further handling in the next below-the floor of one building being level with the upper part of the next. The slope may therefore be regarded as a series of steps, on each of which are situated buildings for one or more stages of dressing. By referring to the plan of the works (Plate IX), which is a reproduction from the drawings of Mr. Kutscher, the peculiarly advantageous character of the topography of the hill, and the manner in which it is utilized will be readily seen. On the first or upper division of the slope is the mouth of the shaft, d, connecting with the Ernst August tunnel; the stone-breaker house, h, containing breakers and coarse sizing

drums, and the buildings, a, b, c, d, containing engines for hoisting and for power, and the hoisting reels. On the second step, some what lower, are two picking-houses, entered on the second story by a track led over a trestle from the breaker-house. The building i is for picking the mine smalls, and K for broken rock. From these picking-houses a track leads northward along the brow of the slope to the dumping-ground. On the third is the ore-ground, and the magazines. Ore from the picking-houses above is either lowered down the slope to it, or is dumped from the trestlework which goes over it. On the fourth step is the coarse separation-house (1), a third picking-house (3), and a small fine separation-house (2). The buildings (2) and (3) are on the sides of the coarse separation-house, and slightly lower. The ore enters the second story of (1) from the oreground by a track passing over one of the two sets of "spitzkasten," which are placed outside of the building. On the fifth division of the slope is one coarse crushing-house (6) with sizing drums, driven by water-power, and sufficiently large to admit of doubling its equipment. On the sixth step is the second coarse crushinghouse (6), of double the capacity of the other and driven entirely by steam-power from the engine (14) on the same level. On the same level is also the coarse jigging-house (7). The middle and fine crushing-house (8), containing most of the fine sizing-drums, is on the seventh step, and on the eighth is the fine jigging-house (9). On the lowest step, which is the bottom of the slope, are the stampinghouse (11), and slime pits, the auxiliary washing-house (10), the office (17), and a number of buildings, used formerly as small stamp mills.

The plan of the works is by no means a perfect one, and it does not seem as though the slope has been utilized to the very best advantage. The main point to be borne in mind in laying down the plan of works where there is a slope available for the purpose is, undoubtedly, that the products shall descend steadily downward, so as to reduce the cost of handling to a minimum. It is consequently a bad disposition to use the ore-ground on the third step for storing finished products, which have to be raised back from the lower steps. These should rather be stored on the very lowest level. The position of picking-house number 3 is extremely awkward, and a better arrangement might have been made, so that the ore from the coarse separation-house to be picked should have gone forward and downward instead of backward. The erection of two coarse crushing-houses was necessitated by the plan of driving one entirely by steam, as the