Chapter XXXVIII: Part 38

“This stupendous structure proves to be a very delicate thermometer. A little sunshine raises the center an inch, (as the expansion can not extend downward,) and produces a horizontal deflection or swelling of an inch and a half. For every fifteen degrees of Fahrenheit, it expands one ten-thousandth of its length, or half an inch. Alternate sunshine and showers of rain, cause the tubes to expand and contract. If one of the tubes was placed on end in St. Paul’s churchyard, London, it would rise one hundred and seven feet higher than the top of the cross. The rivets that unite the plates are an inch in diameter; they were put in red-hot, and beaten with heavy hammers, and in cooling, they contracted so strongly as to draw the plates together with a force requiring four to six tuns to make them slide on each other. The tubes were raised from their position afloat on the water, by means of a Brahmah hydraulic press, into which the water was injected by powerful steam-engines. The force exerted by this power would throw water nearly twenty thousand feet high; more than five times the hight of Snowdon, the highest mountain in Wales, and almost five thousand feet higher than the summit of Mont Blanc. The greatest number of men employed at any one time on this bridge, was two thousand, and the fatal casualties were seven. The second tube was floated to its place December fourth, 1849, and the opening of the bridge by the passage of cars took place March fifth, 1850. It may be deflected thirteen inches without injury, and would bear a weight of one thousand tuns.”

THE SUSPENSION BRIDGE.

In the same vicinity, and over the same strait, is the great suspension bridge, which, when it was finished in 1826, was deservedly esteemed one of the wonders of the world, and is still entitled to hold that rank. It is indeed a stupendous structure, of which the full details may be learned from the official reports; but the following are among the principal facts. It is one hundred feet above the water, so that the ships, even those of a large size, are not impeded, and can pass under it without lowering a sail or a spar. The bridge is built out upon arches from both sides of the river, to a certain distance, leaving the space between the points of suspension, five hundred and sixty feet. The platform is about thirty feet wide. The whole is suspended from four lines of strong iron cables, by perpendicular iron rods, five feet apart. The cables pass over rollers, on the tops of pillars, and are fixed to iron frames under ground, which are kept down by masonry. The weight of the whole bridge between the points of suspension is four hundred and eighty-nine tuns. The massy materials of which this bridge is composed, the admirable manner in which they are locked together, the great elevation at which it crosses this grand strait, its persistence without sign of failure during more than a quarter of a century, its importance as a connecting link between England and Ireland, and the result of this early effort to conquer formidable physical difficulties, fill the beholder with admiration and delight, and do lasting honor to Mr. Telford, the distinguished architect.

GREAT RAILWAY SUSPENSION BRIDGE AT NIAGARA FALLS.

We have before, on page 265, given some account of this vast structure as it was, when so far completed as to be used for ordinary passage. But we advert to it again here, both because it has since had added to it the superstructure for railway-trains, and also that we may bring in comparison, the first suspension bridge ever attempted, (an account of which has been given,) and one of the last and largest ever undertaken. The first train of cars passed over this bridge on the ninth of March, 1855, from the Canada to the American shore, the engine and tender being crowded with people, having the English and American colors flying, while bands of music were playing alternately the national airs of Great Britain and of the United States. The opening of this mighty and magnificent structure, well worthy of being classed with the world’s wonders, really forms an epoch in the history of the world. It unites with strong iron bands two countries, to the intelligence and enterprise of whose inhabitants the bridge owes its existence, and stands a fitting monument. Its strength can never be fully tested; the weight of a fully laden train being but a trifle in comparison to its capacity. A train of eight cars, filled with passengers, two baggage-cars, locomotive and tender, weigh but about one hundred and thirty tuns; this being only one-sixtieth of its immense capacity. The railway portion of the bridge is leased to and controlled by the Great Western railway company, and has laid upon it tracks of three different gauges, _viz._, the New York Central, four feet and eight and a half inches; the Elmira and Niagara Falls, six feet; and the Great Western, five feet and six inches, thus affording facilities for the transit of both passengers and freight, without change of cars. The following statistics will give some idea of this immense structure and its capacity.

Length of span from center to center of towers, 822 feet.
Hight of tower above rock on the American side, 88 feet.
Hight of tower above rock on the Canada side, 78 feet.
Hight of tower above rock on the floor of railway, 60 feet.
Number of wire cables, 4
Diameter of each cable, 10 inch.
Number of No. 9 wires on each cable, 3,659
Ultimate aggregate strength of cables, 12,409 tuns.
Weight of superstructure, 750 tuns.
Weight of superstructure and maximum loads, 1,250 tuns.
Maximum weight the cable and stays will support, 7,200 tuns.
Hight of track above water, 234 feet.

OTHER IMMENSE BRIDGES.

At Peru, in Illinois, is the great bridge of the Illinois Central railroad, which is thirty-five hundred feet, or nearly two-thirds of a mile long. This is perhaps the greatest work of the kind in all the western states. It reaches from bluff to bluff, is seventy-five feet in hight, and contains over one million feet of lumber, beside immense quantities of iron and stone. The top is covered with tin, and made water-tight; the trains of cars are to run on the top of all; and beneath them, and between the frames, pass the roads for wagons; while underneath all are the river and canal. An ornamental railing is placed on each side of the track.

Another large bridge, on the suspension principle, is that over the Mississippi, near St. Anthony and Minnesopolis, in Minnesota. The work consists of a wire suspension bridge, of one span of six hundred and thirty feet, having seventeen feet of roadway, connecting the western bank of the Mississippi river with Nicollet island, about one hundred yards above the first break of its waters into rapids above the falls.

But perhaps the largest bridge ever built, will be, when completed, that now erecting over the St. Lawrence, called the Victoria (railroad) bridge, which is to be an immense iron tube, ten thousand, two hundred and eighty-four feet, or nearly two miles long. It is to be set on twenty-four piers, from two hundred and twenty to three hundred feet apart. At the highest point it will be some sixty feet from the water; and it is estimated that it will take at least five years to finish it. These are some of the largest bridges, (in addition to those already particularly mentioned,) ever erected in any part of the world.

THE HIGH BRIDGE AT HARLEM.

The High bridge at Harlem, a view of which is given in the cut below, forms part of the immense works erected to bring the water of the Croton river into the city of New York. The dam at the river, which is seventy feet wide at the bottom, seven feet wide at the top, and two hundred and fifty feet long and forty feet high, creates a pond five miles long, covering a surface of four hundred acres, and containing five hundred million gallons of water. From this the aqueduct proceeds, sometimes tunneling through solid rocks, crossing valleys by embankments, and brooks by culverts, till it reaches the Harlem river, a distance of thirty-three miles. It is built of stone, brick and cement, arched over and under, and is made large enough to discharge sixty millions of gallons every twenty-four hours. It crosses the Harlem river on a magnificent bridge of stone, fourteen hundred and fifty feet long, having fourteen piers, eight of them bearing arches of eighty feet span, and seven others of fifty feet span, one hundred and fourteen feet above tide-water at the top. The aqueduct then passes on to a first, or receiving reservoir, which covers thirty-five acres and will hold one hundred and fifty million gallons, and thence to the second, or distributing reservoir, which holds twenty million gallons, whence it is distributed by pipes through the city. The entire cost of the work has been fifteen million dollars.

THE BOSTON RESERVOIR.

The mention of the High bridge at Harlem, and its connection with the aqueduct which brings the Croton water to the city of New York, suggests some notice of the aqueduct by which water is brought to the city of Boston, Massachusetts. So early as 1795, an association was formed in Boston for supplying the inhabitants with pure water; and for years it was brought from Jamaica pond, in Roxbury, some four miles distant, in logs which were bored for the purpose. These logs were capable of supplying some fifty thousand gallons daily, which could be raised to the hight of forty-nine feet above tide-water. This supply, however, was soon found inadequate to the wants of the city, though in 1845, some fifteen miles of pipes had been laid, and some three thousand houses were regularly supplied with water. A plan was therefore formed in 1845, to supply the city with water from Lake Cochituate, or Long pond, as it was formerly called, about twenty miles west of Boston. This lake covers a surface of some six hundred and fifty acres, is seventy feet deep, and drains the springs, it is supposed, of some eleven thousand acres. Its elevation is one hundred and twenty-four feet above spring-tide, so that the descent is such as to make the conveyance of water to the city both easy and sure. The water is carried in a brick conduit or tunnel, high enough for a man to walk upright in, as far as the receiving reservoir in Brookline, and from there is taken in thirty and thirty-six inch pipes to the distributing reservoir on Beacon hill, in Boston. It is this reservoir, a view of which is given in the cut beyond, from which the water is distributed in pipes throughout the city. The average daily supply of water needed for the present population of Boston, is about five million gallons. The water-works are capable of supplying twenty million gallons daily; and the Cochituate lake is capable, (by laying down another main pipe,) of supplying forty million gallons daily. The supply of the lake is fully equal to the wants of half a million of people.

AQUEDUCT AT THE PEAT FOREST CANAL.

This aqueduct forms part of the Peat Forest canal, which is a branch of one of the canals extending out from Manchester in England. The latter city is the great center of the cotton manufacture for England, and perhaps the principal manufacturing town in the world. Before the invention of what was called the _spinning-frame_, in 1767, the entire imports of cotton into Great Britain did not amount to four million pounds a year, and the value of exported cotton goods was not over one million dollars. But so rapid has been the improvement of machinery, and the increase of manufactures, that in 1840 the imports of cotton amounted to the prodigious quantity of nearly six hundred million pounds, of which nearly five hundred million were manufactured. And in 1854, these imports amounted to nearly nine hundred million pounds, of which about the same proportion was manufactured as in 1840. Of this immense manufacture, Manchester is the center; and to this may be added various other manufactures, as in silks, worsteds, machinery, &c., &c., &c. As a consequence of this immense business, seeking, of course, outlets to market, Manchester has become a great center of internal navigation. So early as 1761, the Duke of Bridgewater’s canal was constructed; and this was soon followed by the Bury and Bolton canal, in 1791; by that to Ashton and Oldham, in 1792; and by that to Rochdale, in 1794. And these, again, are connected with other canals in such a manner as to establish an easy communication with the eastern, central and southern counties, including the ports of Hull, London and Bristol, as well as Liverpool, which, of all others, is _the_ port of Manchester. It is on one of these side canals that the aqueduct, a view of which is given in the cut above, is located; or rather, it forms part of the canal itself. It is not so much to be noted for its greatness or expensiveness, as for the fact that it was among some of the earliest structures of this kind, which have since become common wherever canal navigation is known.

THE THAMES TUNNEL.

A _tunnel_, in engineering, is a subterranean passage cut through a hill, or under a river, for the purpose of carrying a canal, road, or railway, &c. One of the most remarkable works of this kind, ever executed, is the tunnel under the river Thames, planned by Mr. Brunel, and successfully executed under his direction. Two previous attempts had been made to carry a tunnel under the river; one in 1799, and the other in 1804; but both were unsuccessful. In 1824, however, an act of parliament, authorizing operations on the plan of Mr. Brunel, was obtained; and shortly after the work was commenced. A short account of the progress of the work will probably be the best mode of conveying a notion of the nature and difficulty of tunneling in general.

Mr. Brunel began his operations by making preparations for a shaft fifty feet in diameter, which he commenced one hundred and fifty feet from the river on the Surrey side; this he effected by constructing on the surface of the ground a substantial brick cylinder of that diameter, forty-two feet in hight and three feet in thickness. Over this he set up a steam-engine, necessary for pumping out the water, and for raising the earth to be taken from within the cylinder, and then proceeded to sink it bodily into the earth. By this means he succeeded in passing through a bed of sand and gravel twenty-six feet deep, constituting, in part, a quicksand, and in which the drift-makers of the former undertaking had been compelled to suspend their work. The cylinder having been sunk to the depth of sixty-five feet, the horizontal excavation was commenced at the depth of sixty-three feet; and in order to have sufficient thickness of ground to pass safely under the deep part of the river, the excavation was made to descend two feet and three inches in every hundred feet. This excavation is thirty feet wide, and twenty-two and a half feet high, and the process of making it may briefly be described as follows.

It was accomplished by means of a powerful apparatus of iron, called a _shield_, and which consisted of twelve large frames, standing close to each other, like so many volumes on the shelf of a book-case, these frames being twenty-two feet in hight, and about three feet in width. They were divided into three stages or stories, thus presenting thirty-six cells or chambers for the miners. The front of each one of these cells was protected by narrow boards, technically called polling-boards, each of which was separately held in its place by an apparatus constructed for the purpose. The miner commenced by removing the upper polling-board in his division of the shield, thus exposing a small portion of earth; into this earth he made an excavation of six inches in depth, throwing the earth behind him, from whence it was removed to the mouth of the tunnel, and from thence raised by steam to the surface of the ground. He then replaced the polling-board, causing it to press against the face of the newly excavated earth, and thus advancing it six inches beyond the other polling-boards of his division. Then successively taking down the remaining boards, excavating the earth six inches behind them, and replacing the boards six inches further in than before, he very soon had advanced that distance over the whole length of his division. All the other miners in the thirty-six cells having done the same, the framework was moved forward, and six inches more of earth removed. It was in this way, by these slow degrees, that the work was finally completed. As the frame-work advanced, it was closely followed by a solid mass of brick-work, inclosing two arched passages. These two passages were separated by a solid wall, three and a half feet at the top and four at the bottom. Other arches, however, were formed in this wall, for the purpose of opening a communication between one tunnel and the other. The whole of the brick-work is laid in Roman cement, and each archway is finished with a lining of cement, a carriage-road, and a narrow foot-path adjoining the central wall.

This immense enterprise was not finally completed without serious delay and apparently insurmountable obstacles. The works were thrice interrupted: in 1826, by the breaking off of the clay, leaving the shield exposed to the influx of the land-water for six weeks; also in May, 1827, and in January, 1828, when the river broke in and filled the tunnel. This was quickly remedied, however, by filling the holes or chasms with strong bags of clay; the structure, on clearing the tunnel of the water, being found in a most satisfactory state. Some time later, the works were suspended for seven years, owing to the want of funds. Parliament, however, after repeated applications, granted an advance for their completion, and the works were resumed and continued, till they were brought to a successful termination. The cost of the tunnel, with the approaches on both sides of the river, was about three million and a half dollars; much less than the cost of the modern metropolitan bridges which span the Thames between Surrey and Middlesex.

RAILROAD TUNNELS.

The establishment of railroad communication has given rise, both in this country and Europe, to some stupendous undertakings in the way of tunneling; one or two of which are worthy of notice as illustrating the nature and extent of this kind of work. And the first of these which we shall mention, and one of the most remarkable, is the Box tunnel on the Great Western railway in England. This tunnel pierces what is called Box hill, between Chippenham and Bath, part of which is four hundred feet above the level of the track. It is ninety-six hundred and eighty feet long, thirty-nine feet high, and thirty-five wide to the outside of the brick-work. The shafts for making and ventilating it, are thirteen in number, and vary in depth from eighty to three hundred and six feet. The excavation amounted to four hundred and fourteen thousand cubic yards; and the brick-work and masonry, to more than fifty-four thousand cubic yards. The number of bricks used, was thirty million. A tun of gunpowder and a tun of candles were consumed every week for two years and a half; and eleven hundred men and two hundred and fifty horses were kept constantly employed for all that time. For a considerable distance the tunnel passes through freestone rock, from the fissures of which there was, at times, an immense influx of water, by which on one occasion the works were interrupted for a period of nine months. On another occasion after an irruption, water was for some time discharged by the engine at the rate of thirty-two thousand hogsheads a day. This tunnel is on an inclined plane of one in a hundred. There are several other tunnels of great extent in England, such as the Kilsby tunnel, on the London and Birmingham road, which is over seven thousand feet long; and the tunnel from Wapping to Edge hill, on the Liverpool and Manchester road, which is over six thousand feet long, and quite a number of others of five thousand, four thousand, three thousand feet long, &c. One of these remarkable tunnels, is that on the South-eastern or Dover railway, a view of which is given in the cut on the following page, which passes through what is called Shakspeare’s cliff, at Dover, (though _the_ cliff to which the poet alluded has been undermined and thrown down, and the name is now given to another part of the same range,) on the north side of the British channel. This cliff is a high bluff of chalk, on the west of the town, the white appearance of which gave the name of _Albion_ (white) to England. There are two openings in the tunnel; and through these the whizzing locomotives fly along the dizzy precipice, as if it were an ordinary highway. There is, also, a _second_ tunnel in the same cliff. This last is called the Abbot’s-cliff tunnel, and is about a mile in length, coming out on the face of the rock about sixty feet above the sea. The track passes along the front of the rampart for about a mile, and then enters the Shakspeare tunnel, which is also about a mile in length. Thence, again, it issues on the face of the cliff, and proceeds to the station at Dover.

In the United States there are quite a number of railroad tunnels of great extent. One of these is the Blue Ridge tunnel, in Virginia, the length of which, when completed, will be forty-two hundred and sixty feet, of which more than half is already (1855) finished. The work has been commenced on each side of the mountain, and is progressing at the rate of about fifty feet a month, at which rate of progress it would take about three years to complete it.

But probably the most gigantic work ever proposed in the way of tunneling, is the Hoosic tunnel, on the line of the Troy and Greenfield railroad, by which it is designed to shorten the passage from the former place to Boston. This immense tunnel it is proposed to carry through the solid rock of the mountain for a distance of some four miles, and to make it wide enough for a double track for the railroad; the expense of doing which is variously estimated, at from four million to six million dollars. By the ordinary method of drilling and blasting, it would take so long a time, and require so large an expenditure, that all idea of thus accomplishing the work has long since been given up, if, indeed, it was ever entertained. And the plan is, by immense boring machines, constructed for the purpose, to make grooves round large masses of the rock, and when these latter are broken up by blasting, to remove them piece by piece. Several such machines have been invented and constructed with reference to this very work, and one or two of these have been found successful in practice, though the immense strain caused by the boring is such as to require corresponding strength in the borer. To give the necessary ventilation, and now and then light to the tunnel, both when in the course of construction, and especially when finished and in use, it is proposed at proper intervals to sink dry wells, or openings from the top of the mountain, down to the tunnel itself; so that the constant stream of air entering the mouth of the latter, at either end, may be always and steadily passing up through these chimneys or ventilators, thus carrying off the smoke of the engines, or any impurities of the otherwise stagnant air. The work, when completed, if it ever is, will be a monument of enterprise and perseverance, unrivaled in the history of tunneling in this or any other country of the world.

THE COLOSSUS AT RHODES.

This was a celebrated brazen image of Apollo, of the enormous hight of one hundred and five Grecian, or one hundred and twenty-five English feet, placed at the entrance of one of the harbors of the city of Rhodes, (anciently Rhodus,) which is about twenty miles from the coast of Lycia and Caria, in the Mediterranean sea. The island of Rhodes is about one hundred and twenty miles in circumference, and was early occupied by a colony of Greeks from Crete and Thessaly, who in time became both wealthy and powerful. Their capital city was on the east of the island; it was built in the form of an amphitheater, and had numerous splendid buildings, among which was a temple to Apollo. Having for a time submitted to the power of Alexander the Great, they afterward refused to assist Antigonus in his war with Egypt, when he sent his son Demetrius against them, with an immense fleet and army. They, however, being aided by Ptolemy, king of Egypt, were enabled to repulse his forces and to oblige him to agree to a peace. And he being thus reconciled to them, in admiration of the courage they had displayed, presented to them all the engines he had employed in the attack, by the sale of which, for three hundred talents, they raised the famous colossus, a view of which is given in the cut.

This immense statue, as already said, was of brass, and was erected in honor of Apollo, the tutelary god of the island, in acknowledgment of the protection he was supposed to have rendered the Rhodians in their recent conflict. It was the workmanship of Chares, (a pupil of Lysippus, a celebrated sculptor and statuary of Greece,) who, with an assistant, was engaged in the work for more than twelve years. The hight of the statue, as already said, was one hundred and twenty-five feet; its thumb was so large that few people could grasp it; and the fingers were each larger than the bodies of statues of ordinary size. It was hollow, and to counterbalance the weight, and render it steady on its feet, its legs were lined with heavy masonry; and within them, were winding staircases leading to the top of the statue, from which one could easily see Syria, and the ships sailing to Egypt. It is supposed to have stood, with distended legs, on the two moles which formed the entrance of the harbor; but as the city had two harbors, one twenty, and the other fifty feet wide at the entrance, it has been supposed to have been at the narrowest. It bore a light, or lantern, so as to serve as a light-house; but whether on the head, or in one of the hands, as represented in the cut, is not certainly known. The statue was erected B. C. 300, and after having stood about sixty years, was thrown down by an earthquake. After its fall, the Rhodians solicited help from the kings of Macedonia and Egypt, and in other countries, to enable them to restore it; and so great was the commercial importance of Rhodes, that their appeal was promptly met by magnificent gifts; but the oracle at Delphos forbade them again to raise the colossus. The statue then remained in ruins for the space of eight hundred and ninety-four years, when, in the year 672 A. D., it was sold by the Saracens, who were then masters of the island, to a Jewish merchant of Edessa, who loaded nine hundred camels with the metal which had composed it, and which, estimated at eight hundred pounds for each camel-load, would have amounted to seven hundred and twenty thousand pounds’ weight.

The character of Rhodian art was a mixed Græco-Asiatic style, which seems to have delighted in executing gigantic and imposing conceptions; for beside this celebrated colossus, (which was one of the seven wonders of the ancient world,) there were three thousand other statues adorning the city; and of these, about one hundred were on such a scale of size and magnificence, that the presence of any one of them would have been thought sufficient to dignify almost any other spot. The architecture of Rhodes was of the most stately character: the plan of the city was by the same architect who built the Piræus at Athens; and all was designed with such symmetry, that Aristides remarks, “It is as if it had been one house.” The streets were wide, and of unbroken length; and the fortifications, strengthened at intervals with lofty towers, did not appear, as in other cities, detached from the buildings which they inclosed, but by their boldness, and decision of outline, hightened the unity and conception of the groups of architecture within. The temples were decorated with paintings, by Protogenes, Zeuxis, and other celebrated artists of the school of Rhodes; and of one of these pictures, it is said, that when taken to Rome, it was the object of universal admiration. The island, after passing through various fortunes, has, for a long time, been part of the Turkish empire.

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MISCELLANEOUS WONDERS.

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Having dwelt so long on the WONDERS OF NATURE, and the WONDERS OF ART, both ancient and modern, we pass to some of the wonders and curiosities of the world of a miscellaneous nature. Some things are wonders only through their associations, as is the case with many of the localities of Palestine, for example, where the Saviour lived and walked, and wrought his miracles of power and mercy. Some are wonders as exhibiting the inventive powers of man, or the progress of our age as compared with another; some as exhibiting the singularities of nature; and some as combining the wonders both of science and art. The steamboat, the printing-press, the air-balloon, the residence of Washington, the hut of the Kamtschatkadale, the spot where the “Pilgrim Fathers” landed, the telegraph, the diving-bell or armor, the prairie on fire, the nest of the African tailor-bird, each of these, and of a multitude of other things that might be enumerated, is, in some way, or for some reason, associated to our minds with what is more or less wonderful, while still it may not be strictly a wonder either of nature or of art. Some of these we propose now to notice, interspersing them at intervals with some of the more miscellaneous wonders of nature, or art, or both, so as to give variety to the pages that follow. And the first of this class of wonders we will notice, is,

YOULE’S SHOT-TOWER.

This edifice, which is one of the best of its class, is situated at the foot of Fifty-fourth street, on the East river, in the city of New York. It is hexagonal in form, and rises to the hight of one hundred and seventy-five feet; being sixty feet in diameter at the base, and gradually growing smaller as it rises toward the top. It forms a most striking object of interest; and is remarked by the multitudes who pass by it going up and down the sound, to and from New York. When we consider the small size of the article to the manufacture of which this lofty structure is devoted, the means appear greatly out of proportion with the result. Formerly in casting shot, the apparatus was merely a plate of copper, in the hollow of which were punched a number of holes. This was placed a few feet above a kettle of water, into which the melted lead descended, after passing through the holes in the plate. But in falling so short a distance, and being so suddenly cooled and hardened, the shot did not acquire a perfectly globular form, a desideratum which is now attained by means of shot-towers. In the tower of Mr. McCullough, the largest shot falls from the summit of the tower to the bottom of a well twenty-five feet below the surface of the earth, making the descent one hundred and seventy-five feet. The size of the shot is determined by the size of the holes through which it passes. The furnaces for melting the lead are situated near the top of the tower; three or four tuns of shot are manufactured per day. This method of casting shot was invented by Mr. Watt, the celebrated engineer, in consequence, it is said, of a dream. He tried the experiment from the tower of the church of St. Mary, Radcliffe, and finding it very successful, obtained a patent, which he afterward sold for ten thousand pounds. There are now several shot-towers in the vicinity of London, and different parts of the world; but none more worthy of notice than the one of which we are now speaking. An iron staircase ascends from the base to the summit of the tower. Arsenic is mingled with the lead in proportion of forty pounds to one tun. In casting, the metal is poured through a tube, but descends through the open space of the tower in a continual stream of silvery drops. As the weight of the lead prevents it from scattering or being blown about like water-drops, the workmen pass to and fro, without danger, close by this fiery cascade. The shot is of different sizes, from number one, swan shot, to number twelve, dust shot. Mr. James McCullough has brought the art of the manufacture of the shot to perfection. Certain portions of his factory are kept entirely secret; and the shot manufactured in New York are not surpassed in the world. The cause of most of the imperfections in the manufacture of lead shot, is the too rapid cooling of the spherules by their being dropped too hot into the water, whereby their surfaces form a solid crust, while the interior remains fluid, and in its subsequent concretion shrinks so as to produce the irregularities of the shot. The patent shot-towers originally constructed in England, obviate this evil, by exposing the fused spherules, after they pass through the cullender, to a large body of air during their descent into the water-tub placed on the ground. The greatest erection of this kind is probably at Villach, in Carinthia, being two hundred and forty Vienna, or two hundred and forty-nine English feet high. The following is the process. Melt a tun of soft lead, and sprinkle round the sides of the iron pot about two shovelfuls of wood ashes, taking care to leave the center clear. Then put into the middle about forty pounds of arsenic, to form a rich alloy with the lead. Cover the pot with an iron lid, and lute the joints quickly with loam or mortar, to confine the arsenical vapors, keeping up a moderate fire to maintain the mixture fluid for three or four hours; after which, skim carefully, and run the alloy into ingots or pigs. The composition thus made is in proportion of one pig to one thousand pounds of melted lead. Two or three tons are usually melted at once in large establishments. A crust of oxyd of a white spongy nature, sometimes called cream by the workmen, covers the surface of the lead, which is of use to coat over the bottom of the cullender. The cullenders are hollow hemispheres of sheet-iron, about ten inches in diameter, perforated with holes perfectly round and free from burs. These must be of a uniform size in each cullender; but, of course, a series of different cullenders, with sorted holes for every different size of lead shot, must be prepared. The operation is always carried on with three cullenders at a time, which are supported upon projecting grates of a kind of chafing-dish made of sheet-iron, somewhat like a triangle. This chafing-dish should be placed immediately above the fall; while at the bottom there must be a tub half-filled with water, for receiving the granulated lead. The cullenders are not in contact, but must be parted by burning charcoal, in order to keep the lead constantly at the proper temperature, and to prevent its solidifying in the filter. The hight from which the particles should be let fall, varies likewise with the size of the shot; as the congelation is the more rapid, the smaller they are. The workman then puts the filter stuff into the cullender, pressing it well against the sides; he next gently pours lead into it with an iron ladle. The center of the cullender being less hot, affords larger shot than the sides. Occasionally, also, the three cullenders employed together, may have holes of different sizes; the shot will then be of different magnitudes. These are separated by square sieves of different fineness, and after passing through other minute processes, are ready for sale and use.

THE EMPEROR FOUNTAIN.

This splendid fountain, a view of which is given in the cut beyond, is one of the most remarkable in the world, and in commemoration of a visit paid to it in 1844, by the emperor of Russia, it was called the Emperor fountain, though since the outbreak of the war between Great Britain and Russia, the name is said to have been changed to that of the Victoria fountain. It is situated in Chatsworth, one of the most luxurious seats of the English nobility; famous for its exceeding beauty and its costly embellishments. Its walks, lawns, parterres, mimic Alpine scenery, conservatories, gardens, cascades, halls, pictures, and sculpture, and music, and fountains, have all been constructed and arranged with consummate taste and with lavish expense. A month would scarcely suffice to visit all that is worthy of observation in this wonderful place, and perhaps few sights could produce a deeper impression of the wealth possessed by the English aristocracy. We have from this munificent storehouse selected a single object to be delineated by the pencil. The Emperor fountain is fed by immense artificial reservoirs on the hills above Chatsworth, covering eight acres of ground, into which various springs and streams have been diverted. Our American ideas of a fountain are usually limited to a beautiful jet of water forced twenty or thirty feet in hight; hence it is with amazement, if not incredulity, that we hear of the fountain of Chatsworth, which throws its jet to the hight of two hundred and sixty-seven feet! Such is the velocity with which the water is ejected, that it is calculated to escape at the rate of one hundred miles a minute!

THE UNITED STATES MINT IN PHILADELPHIA.

The United States mint was founded in 1790; and the business of coining commenced in 1793, in the building now occupied by the Apprentice’s library. In 1830, it was removed to the fine building it now occupies, on Chestnut street, above Olive street. The edifice is of white marble; and the north front, opposite to Penn square, is one hundred and twenty feet long, with a portico of sixty feet long, having six Ionic columns; while the south front, on Chestnut street, has a similar portico. Since the enormous influx of gold from California, the United States mint has become an object of more than common interest and attention; and the place is usually filled with visitors, watching the various processes the metal goes through before it comes out in finished coin. The machinery and apparatus by which these are accomplished, are of the most complete and perfect character. The rooms in which the smelting, refining, and alloying are done, are spacious apartments in which a large number of workmen are employed. Heaps of the rich ores are to be seen lying around, just as they were extracted from the mines, or gathered in dust from the sands of the mountain-streams of California. Bars of the pure metal, of thousands of dollars’ value, are passing through hands, which like those of the fabled Midas, seem to turn all they touch into gold. The heat of this place is very great; the fires glow with the intensity of those in a foundery; the men, in appearance, resemble the workmen in a smithy; and there is a suffocating sensation of hot air, steam, and perspiration, penetrating the atmosphere, which is anything but pleasant to experience, especially when one is palpitating under the heat of a summer temperature, without the freshness of the open air to modify and alleviate it. Crucibles are handled with iron tongs, and cotton or woolen mittens; and the metal is shaped into bars, and then reduced to the requisite fineness. All this takes place in one apartment.

In another room, is seen a most beautiful steam-engine, which drives all the rolling and stamping machinery. It is of one hundred horse-power, and works the rolling machinery, the draw-benches, and the cutting presses. It is called a steeple-engine, and has two cylinders; its boilers are forty feet long, and forty inches in diameter; and the steam from them also moves a ten horse, and a five horse engine, in the separating and cleaning apartments. This main engine is of the most elegant workmanship, polished like a piece of cutlery, and works with the most admirable precision and regularity, without the least perceptible jar, and with scarcely a noise. From this room, the visitor walks into that where the rolling machines are at work, turning out the metal to the proper degree of thickness which each particular kind of coin requires. The metal is cast into ingots fourteen inches long, and about five-eighths of an inch thick; and these are rolled to very near the proper thickness, when they are passed through the draw-benches to equalize them. The strips are then cut at the presses, which is done at the rate of about two hundred to two hundred and sixty per minute. There are fourteen men employed in this room, two at each pair of rolls. The pieces, as thus cut, then pass to the adjusting room, where each piece is weighed separately, and if too heavy, filed down, or if too light, or any way imperfect, thrown back to be remelted. There are fifty-four females employed in this room. The pieces are next taken to the milling and coining room, where from two hundred to four hundred are milled in a minute, according to their size. In another apartment, the coins are cut with a punch to the desired size, and then stamped. For this purpose they are placed, by a person seated at the machine, in a perpendicular tube, down which they descend, one at a time, being seized as they drop by a part of the machinery, which pushes the coin under the stamp, whence it falls beneath the machine into a glass-covered box. This part of the process used formerly to be performed by a press which required eight men to work its lever and screw; but now the process requires scarcely any manual labor except handling the various pieces of coin. The rapidity with which the pieces are executed, is surprising; being at the rate of from seventy-five to two hundred per minute. Cents, dimes, dollars, eagles and double-eagles are turned out with equal facility, the process being the same in all. Some idea of the extensiveness of these operations may be had, when it is stated, that, in a single month, lately, nearly three million pieces of gold, silver and copper were coined, and that over four million dollars in value are coined every month.

In addition to the other attractions of the mint, there is a most extensive cabinet of coins, ancient and modern, of various nations, which is one of the greatest of curiosities to be found, probably, in any part of the world. Here, too, are exhibited specimens of all the existing or past coins of the mint itself, and models or specimens of any intended coins. The officers and attendants of the mint are polite and attentive to all visitors, and endeavor to make their visit one of instruction as well as amusement; and any one, by calling at appointed hours, can go through the various apartments of the building, and see the various processes which have thus been described.

THE AIR BALLOON.

From the earliest ages, the notion of flying in the air, either by wings or by supernatural agency, seems to have been in the minds of at least some of mankind; but the idea of the _balloon_, consisting of an envelope containing something light enough to make it rise and float in common air, is comparatively of much later date. It is said that the first definite notion of the balloon originated with a Jesuit, by the name of Francis Lana, who in 1670 conceived the idea of raising metal balls in the atmosphere, which had previously been exhausted of air, but which should be at the same time so thin, as to weigh less than their bulk of air. The experiment, however, he never tried, as, in his age, it was not believed that God would allow an invention to succeed, by means of which civil government could so easily be disturbed. Later experiments have proved that strength to resist the external air is incompatible with the necessary degree of thinness in the material. From this period, one hundred years elapsed, before the idea of raising a body in the air, by means of its being lighter than the air whose space it occupies, was pursued any further. In 1782, an attempt was made to raise bodies filled with hydrogen gas, a substance which, as is well known, is lighter than atmospheric air. The experimenter succeeded, however, in raising nothing heavier than a soap-bubble. In the same year, the brothers Montgolfier, paper-makers at Lyons, attempted to raise a paper balloon by means of hydrogen gas. Being unsuccessful in this, they conceived the idea of applying fire underneath a large balloon of paper built upon a framework of wood, and containing a receptacle for fire in the place where, in modern balloons, the car is suspended. This experiment being so far successful as to show the correctness of the principle, they next made a balloon of linen cloth, and kindled under it a fire made and fed by bundles of chopped straw, apparently with the impression that it was the smoke rather than rarefied air which had the ascending power. The balloon, thus inflated, rose about a mile in a direct line, and then described a horizontal line of about seven thousand feet, after which it gradually sunk. The next attempt was upon a balloon of lutestring dipped in a solution of India rubber, and filled with hydrogen gas. The experiment at first failed, but on the twenty-seventh of August, the same year, at Paris, the balloon rose beautifully to a great hight, and fell about twelve miles off. Soon after, animals (sheep, ducks, &c.) were sent up; and on the fifteenth of October, the first human aeronaut made an ascent of a hundred feet. The balloon, however, was held by a rope, and connection with the earth not entirely severed. A month later, on the twenty-first of November, the daring feat of completely leaving the earth was performed by two gentlemen, one of whom was M. Rosier, and the other the Marquis d’Arlandes. The balloon was a _Montgolfier_, or one in which the elevating power was air rarefied by fire. The signature of Benjamin Franklin, who at that time was American minister to Paris, is upon the official paper describing the balloon, its dimensions, &c. It was seventy feet high, forty-six in diameter, and carried a weight of from sixteen to seventeen hundred pounds; it rose to the hight of five miles in twenty-five minutes. When the aeronauts wished to ascend still higher, they shook a bundle of straw into the flame; when they wished to sink, they let the fire smolder, or extinguished it with a wet sponge. The attempt was successful, and the voyagers alighted in safety, after an absence of a little less than an hour.

The first trial of a hydrogen balloon was made a week later, from the garden of the Tuilleries, just after sunset. It ascended two miles with perfect ease; its occupants here came in sight of the sun, which seemed to rise again, as at morning, in the east. The balloon and its two travelers were the only illuminated objects, all the rest of nature being plunged in shadow. During the next two years, many ascensions were made by different persons, and successive improvements and inventions were added. The parachute was invented in 1784, and the first attempt at steering a balloon was made in this year, but without success. In 1802, M. Garnerin descended successfully from a great hight by means of a parachute. In 1806, two aeronauts ascended to such a distance, that they came into an atmosphere so rarefied as to burst the balloon. The remnants, however, broke the fall, and they descended in safety. From the beginning of this century to the present day, but little progress has been made in an art which seems destined to be of little service to mankind. No possible means of guiding the balloon have yet been discovered, or any practicable method of giving it a horizontal motion, so as to withdraw it from the influence of winds and currents. It has now become a mere toy, and for any practical or scientific purpose, has long since ceased to be of the slightest account.

One of the largest balloons ever constructed is that of Mr. Green, a celebrated English aeronaut, which is called the Continent, and has made many ascensions from London and Paris. The following account of an ascent from the Hippodrome at Paris, in 1848, is from a leading French journal. It is from the pen of Theophile Gautier, an eminent Parisian romancer and _feuilletonist_.

“Last Sunday, about five o’clock in the afternoon, Green’s balloon sprung from the inclosure of the Hippodrome into the blue abyss of the heavens. The ascension of a balloon is certainly not a novelty at the present day; but an aerostat, like the one belonging to Green, is not of the ordinary class: its colossal dimensions, the extraordinary care with which it is constructed, the comfort of its arrangements, make it the wonder of aerial navigation, and place it in the rank of a vessel of a hundred guns. To see it swelling its enormous taffeta case under the net-work of cords which holds the car lined with red velvet, one feels perfectly at ease as to the dangerous chances of a voyage through the air. It would seem safer than an excursion in a diligence or upon a railroad. Admitted into the reserved inclosure, we of course saw the departure, being near the spot. Nothing could be more quiet or more gentle. Mr. Green, in a black coat and white cravat, like a gentleman going out to dine, stepped into his carriage—I should say his balloon—with confidence and self-possession. A charming young English girl, accompanied by a friend, had already taken her place in the boat or car. She was calm and smiling; animation tinged her cheeks slightly, but it arose rather from embarrassment at seeing so many eyes fixed upon her, than from any fear whatever. Her intelligent face breathed that confidence in the inventions of human genius, which characterizes the English and American races. A Parisian lady would have screamed loudly.