Whether to project myself head or feet foremost, was a question, but I gave the head the preference. I now saw the use of the knee-shields, but I substituted hands and toes for hands and knees. I thought there could be but one such passage in any mine, and took courage. I was right in the first idea, that is, I did not find another such passage; but the courage was out of place, for other passages were so much worse. The next was nearly vertical, and equally sparing in the space it afforded, the dimension of a section of it, I mean, for in length it was certainly ample enough. I had given the honorable position to the head in the previous instance, but fearing an apopleptic attack if I exercised the same discrimination here, I assigned the foremost position to my boots. Thus proceeding, upward and downward, horizontally and winding, we at length came to what was called the deepest part of the mine, but instead of turning back, we continued through the same intricate tube till we were again at the mouth of the mine where we entered it. I came out, a cylinder of mud, "of the earth, earthy," in a sense in which it was not true of me when I entered it.

The characters of the mountains on opposite sides of the Quebrada are altogether different. Both contain more or less of stratified rock, but the strata have different positions in the two mountains. The dikes have different directions, and the aspect of the two is quite different. One is not therefore entirely unprepared to learn that tin is found almost exclusively in one, while silver alone is found on the other.

The mine which I entered can hardly be regarded as a single vein. In every direction are branches more or less extended, often but a few yards, but some⚫ times a hundred feet or more. At the extremity, and often at intermediate points, is a miner with his lamp hung by a hook to his cap, loosening the veinstuff from the rock in which it occurs, so that though there is nowhere a collection of workmen in the mine, yet the inside of the mountain for a great space around, is full of living beings. When the hour of labor for one set of hands has expired, their rush from the mouth of the cave together, and dispersion in different directions down the declivity, is quite an animated scene.

In this mine the ore, which is the Oxide of Tin, is found for the most part disseminated through a matrix of clay. The mass of it is in small crystal line particles, but these particles are often adherent so as to form pieces weighing several pounds. Recently, however, and in the deeper parts of the mine, they have found ore in the state of solid rock, not associated with clay, and which it has been found necessary to blast. Large quantities of gunpowder are now used in the mine, not because the solid ore is better, if it is as good, but because by obtaining this they get nothing but ore, while in the other case they have to lift by their own muscles twice as much clay as ore, through that long passage to the mouth of the mine.

The ore thus brought to the light is carried by lamas, about a mile, to where the process of washing is performed. The clay ore is first washed to free it from the clay. It is sometimes sufficiently pure without further process for the market. If not, it is treated like the rock ore. The rock ore is first crushed by a very rude instrument, namely, a large rock with a somewhat regular oval surface, placed upon another which has a nearly plane surface. A wooden bar is fastened to the top of the rocking stone, and two men keep it in motion, watching their opportunity on each side to remove that which is sufficiently powdered, and almost at the same instant throwing under the pieces to be crushed. The earthy portion breaks to powder, while the ore breaks only into fine sand. By washing, that is, by spreading it upon a slightly inclined surface and allowing a small stream of water to flow over it, skilfully stirring it in the mean time, nearly all the earthy parts are separated, while scarcely any of the ore is lost. In this state they call the ore of tin as well as of copper, barilla. And in this state it is found profitable both to buyer and miner to sell it.

The Government allows the copper barilla to be exported, but for some rea

sons, it has required that tin shall be exported only in the metallic state. It has therefore been necessary to bring charcoal for smelting from the valleys of the Eastern Andes, and it has been difficult for proprietors to compete with the productions of similar mines in other countries. The evil has become so great that some remedy must come from some source. If in no other way, the pressure upon the Government will be so great as to compel them to yield, for it is natives, and not foreigners, who own these mines and work them.

But it is hoped that there may not be a necessity even for that. Within a few weeks coal has been discovered in this immediate vicinity. I have not seen the bed, but I have seen abundant specimens of the coal. It is not a part of the great coal series. Probably it is a product of the tertiary period, like the Brona coal, and therefore cannot be relied on as if it were of an older date, but it may be sufficient for the mining purposes of the region. It is found on the pampa, and it is by no means improbable that these extensive plains, which hitherto there has been thought to be no occasion at all for examining mineralogically, may every where contain the necessary fuel for mining purposes.— What a provision of Providence it would seem, if such mineral treasures have been stored up; but where forests cannot grow, it shall be found that when these plains were below the level of the ocean, perhaps before the minerals were deposited in their present positions, the vegetation of these mountains (then islands) was treasured up for the miner's use in these later times.

The tin from South America is employed almost exclusively for purposes of dyeing it being very much superior to that smelted with mineral coal for such purposes.

These mines have been worked on a small scale for many years, even by the Spaniards; but foreigners, merchants in the cities on the Pacific side, have given a new impulse to the business, by purchasing with avidity either the metal in bars, or the barilla, which they send to England to be smelted. The business as yet has not become a leading interest of the country, but I see no reason why it should not rise to very considerable importance. I am persuaded that the ore exists in immense quantity. It is perhaps inexhaustible. In this immediate vicinity the present annual production is probably not far from three thousand tons, and brings here generally $180 per ton.

A SULPHUR MINE.

Mr. E. Pinyret, an artist of Mexico, has published in that city, a minute description of a daring ascent to the summit of the celebrated volcano, Popocatepetl. Probably the crater of that furnace has never been so well described as in this account.

In spite of the ridiculous orders of the Governor of Puebla, who calls himself proprietor of the volcano, I managed to ascend it, descend into the crater,. paint there, and sleep there.

After having mounted about 3000 feet upon the steep side of the eternal snows that crown the volcano, it appeared to me impossible to sit down to take a lunch. The lip of the wide mouth of the crater, which appears to you suddenly, presents an angle almost acute, the outer side of which is covered with ice and snow, that has been partially melted by the warmth of the summer's sun. The interior is nearly perpendicular; for half the distance down there is a steep path made by the workmen of the sulphur mine. The path descends on pieces of lava, scoriæ and ashes, to a projecting point of lava that overhangs the crater. On this point a work place has been constructed for the working of the mine, and alongside is a cabin for the workmen. The cabin resembles a dog's kennel; but it is the hotel of Popocatepetl. From the cabin down to the crater is about two hundred yards; but in descending by the cord the adventurer alights on the declivity of the sulphur mine, and then descends another hundred yards to the bottom. It is with difficulty that the voice of one below

can be heard; and for a person below to hear another above is impossible. That may give an idea of the distance, which has never been accurately measured.

The bottom of the crater might be compared to a vast caldron, that had been filled with a boiling mixture, the scum of which had remained on the sides and suspended over the hollow left by the cooling This scum is the solfatara, the sulphur mine, which has been the object of a long-standing law-suit between the two rival claimant companies.

The void over which the solfatara rests is beyond doubt in a state of fusion, and liable at any day to new eruptions, which may have an important influence on the sulphur mining companies' stocks. In some parts of the crater streams of smoke escape, and in other parts there are puffs with detonations. A cane thrust down one of these vents is burnt off in a very short time-pretty strong evidence that the fire is not far distant. The sulphurous gas from these chimneys is suffocating. In some places it has sufficient strength to hold together, and be visible above the top of the crater; and little streams of gas, which are soon lost, escape all about the sides.

The upper circumference of the crater is about four and a half miles, but it would be impossible to walk around it, as is done at Vesuvius. The crater of Vesuvius, compared to that of Popocatepetl, is like half the shell of a hen's egg compared with half the shell of a goose's egg. Only the crater of Ætna can be placed on a parallel with Popocatepetl, but even that has not the majesty, nor the regularity, nor the remarkable character of the latter.

The picture which I have made of the interior of the crater of Popocatepetl, and which, I believe, is the only one that has been made, represents the half nearest Puebla. The different layers, as placed by succeeding eruptions, are plainly visible. The topmost layer is about twenty-five inches in depth, and is composed of black scoria. Upon this last layer is a coat of ice fifty feet thick, running up to a sharp edge, and tinged with a beautiful green on the inner surface. The ice is full of fissures and rough projections, inaccessible to man, so that I was unable to place myself upon any part of it to make a panoramic design, as I wished to do. Looking down upon the valley, nothing can be seen except the vapors of the tierra caliente (lowlands), and three or four high peaks-among others, the peak of Orizaba, towering above the clouds.

The other half of the interior circumference, which is next to Mexico, is more picturesque by reason of its rough character. I made a drawing of it, but the overseer of the rancho of the sulphur font, after permitting himself to be seduced to permit me to make the ascent with my men, stole the drawing, to prove his zeal and fidelity to the Governor of Puebla. I had sent to the latter for authority to ascend, and he had answered negatively, with an additional order probably to take my sketches. The overseer opened my box of colors whilst I was resting after my descent, and took one of the six designs I had made during the trip.

Here is some advice to those who may wish to ascend Popocatepetl: they can leave Mexico and arrive at the rancho of the sulphur font, and at 6 o'clock on the next morning begin the ascent. It is useless to attempt to mount the crater before sunrise; it is five hours' walking from the rancho to the crater; it would be necessary to start at midnight, and the route through the forest, over trees blown down by hurricanes, and over ice, would be extremely dangerous. I think that no one will get to see the sun rise from the crater without staying there over night; but for two months at this season of the year the beautiful panorama is hidden by the mists of the tierra caliente. After leaving the rancho you can travel two hours on horseback through a fine forest and over volcanic cinders, to the beginning of the ice. The remainder of the journey, up 3000 feet of perpendicular height, over ice and snow, must be accomplished on foot.

The inclination of the lower part of the ascent on the ice is about 35 degrees; it is terrifying to look back. The declivity, becoming more steep by the melting of the ice, is more perceptible below than above; the whole having the form of a convex curve, exceedingly difficult to mount. There is but one

recipe for those making the ascent; it is to have a vigorous pair of legs. Mine unfortunately carry the weight of seventy years, and they failed me several times on the route. It is scarcely necessary for me to say that the five persons that I had invited to help me, abandoned me completely on the ice.

The last ascent demands three hours. The following day the traveller can descend and arrive at the city of Mexico. I started from the crater at 4 o'clock in the morning, and arrived in the city at 5 in the evening. The whole trip, to be well made, demands three days, and thirty dollars, and the permission of the Governor of Puebla, who, unfortunately, is no friend to the natural beauties of his country.

It is a common error to believe that the rarefaction of the air on the summit is injurious to respiration. The excessive fatigue of the journey takes away the breath, and breaks down the physical forces, but that is all. Once arrived at the top, and sheltered by the crater, there is no feeling of pressure. The workmen who labor two weeks in succession in the sulphur mine, often descend and mount twice in a day over the icy steep of which I have spoken; but for all that they have sound lungs.

GWYNNE'S REACTION CENTRIFUGAL PUMP.

At a period when several valuable workings have been either partially or wholly neglected, from the absence of any efficient and economical means to get rid of the water, it becomes a matter of much consequence to the miner to be made acquainted with any new aids which recent improvements may afford him for this purpose.

This pump is constructed upon an entirely different principle from all the ordinary pumps in use. The principle is the same as that of the blowers for the furnaces of steamboats and for blast furnaces. Every one knows the irresistible force with which the air rushes out of these blowers upon the fires. So in this case, the water enters at the sides of a disc, the rapid revolution of which imparts to it a centrifugal force, which causes it to rush out at the spout with wonderful velocity. Some idea of its torrent-like force may be obtained from the fact that it causes a hundred gallons to pass through a two-inch pipe in a minute at a moderate speed. These pumps are extremely portable, easily set in operation, and not liable to get out of repair, or to be choaked by pebbles, or other foreign matter. In mines, or excavations of any kind, they are the most convenient, rapid and substantial machines we possess for the removal of water, and must unquestionably supersede all other pumps for such purposes.

From an examination of the working of these pumps, we recommend them to the attention of all parties having use for such machines, confident that they will confirm our opinon of their superior merits. The Union Power Co. of the United States, located in this city, is the only establishment at which these pumps can be obtained.

A NEW MOTIVE POWER.

To the Editor of the Mining Magazine.

The necessities of the age require a new motive power. The steam engine has become burdensome to man; it has had its day; the progress of the age requires a more portable and powerful agent than steam. The caloric engine is a failure, and the carbonic acid engine is difficult to manage. Who is to confer the blessing upon mankind of giving them a new motor? Within the life-time of many now living, a new engine, simple, cheap, compact, and powerful, is to take the place of the cumbersome semi-barbarous machine called Watt and Fulton's Steam Engine, which will only be exhibited in museums, where useful implements shall be kept to show the progress of civilization.

MOTOR.

RECENT PUBLICATIONS.

THERE is a large number of volumes constantly issuing from the press, the contents of which relate more or less directly to the objects of the Mining Magazine. Some treat of distinct branches of the general subject, and are able, instructive, and valuable. Such cannot be passed over without notice by us, if we would carry out in full the plan of our publication. Happily these works are of such importance as often to become the subject of a general article, but by far the larger number contain hints and observations, or facts, and summary statements, of useful and interesting information to all our readers. It is, therefore, to furnish those who are interested in mining operations with a knowledge of whatever is published in relation thereto, with criticisms upon the contents, worth and merits of each work, that we have added the following additional department to the original plan of this Magazine. Of the manner in which it will be executed, we will venture to say a word. It will be conducted with a liberal hand, not consisting of mere notices of the contents and literary merits of a book, but extracts will be made whenever necessary to illustrate the nature of the volume, and whenever they possess interest and instruction for our readers. Such a course is the only one consistent with advantage to publishers of books, and the readers of a periodical; and while it may be acceptable to the former, it cannot be otherwise than gratifying to the latter. On all other points, whatever may be written must be judged by its own merits.

Scenes and Adventures in the Semi-Alpine Region of the Ozark Mountains of Missouri and Arkansas, which were first traversed by De Soto, in 1851. By Henry Rowe Schoolcraft. 8vo. pp. 256. Philadelphia-Lippincott, Grambo & Co.

The terın Ozark, as used in this title, is applied to a broad, elevated district of highlands, running from north to south, centrally, through the States of Missouri & Arkansas; on the east is the deep track of the Mississippi, and on the west the plains or deserts which stretch below the Rocky Mountains.

It was as early as 1818, when the adventures described in these pages took place, and it may occasion surprise in the reader at their publication at this late day. They occurred upon the first and only attempt which has been made to identify the march of De Soto, the bold Spanish explorer, west of the Mississippi, and they present reminiscences of observations which belong to the history of the discovery and settlement of the country.

The Appendix, which comprises about half the volume, consists of a number of papers likewise written at that early day, upon "The Mineralogy, Geology, Antiquities and Geography of the Western Country." It presents a very complete description of the Lead Mines of Missouri, with cuts representing the furnaces then in use. The state of these at that period-the year 1818, is thus described :

Respecting the present state of the lead-mines, it is only necessary here to add, that they are worked in a more improved manner than at any former