this scene, and not one can forget the entire composure of the Earl of Rosse's manner. While every other person seemed anxious and fearful, he directed the men as collectedly and easily as if it was one of the most ordinary occurrences of life; and his only answer to the many proffered suggestions of the bystanders was, "There's no fearthere's no hurry."

When the metal had settled, it was drawn by a capstan into a heated oven, and built in, where it remained for sixteen weeks, annealing. The great difficulty experienced in producing large reflectors is, that in cooling the metal generally cracks; and when this does not occur, the number of holes often found in the solid mass renders it of no use. Lord Rosse has the merit of overcoming completely both these obstacles. The plan usually adopted in casting is to make the shape in sand; this substance, however, in his lordship's experiments, allowed the under portions of the metal to remain heated as long as the upper, and both surfaces setting together, left the central portions the last to cool, which thereby caused warping and cracking in the speculum. Lord Rosse thought that if the metal was cast in the shape of iron, its high conducting power would cool the under surface rapidly, and that the cooling would extend itself gradually to the top. This he found, on trial, to be the case; but the air and gas that is always mixed with the fluid metal not having the porous sand to allow its escape, rose through and filled with holes the speculum, and consequently destroyed it. The problem now was, to find some substance of sufficiently high conducting power to cause rapid cooling; but, at the same time, sufficiently porous to allow the escape of air when the metal was poured on it. In a happy moment the noble mechanic solved it. He thought

LORD ROSSE'S WORKSHOP.

that by binding together layers of hoopiron, and turning the required shape on them edgewise, that the interstices would be too small to let the metal pass, and large enough to give the air exit. The existence of the six-foot speculum is a magnificent proof of the truth of the calculation. Nothing could have answered more fully. We should be proud to think that the greatest scientific triumph was not the creation of a happy chance, but the result of reason.

The speculum being cast, was left for sixteen weeks in the annealing oven; and we may well envy, but can scarcely imagine, the feelings of its maker when, on removal, it was found without spot or blemish, The surface had now to be ground and polished. The figure required for the surface of a reflecting speculum is that of a parabola. There is, in general, very great difficulty in producing this curve; and it has been such a terror to opticians that few can be found willing to undertake a speculum of larger diameter than six or eight inches. However, Lord Rosse, by a combination of motions, both of the speculum and polishing tool, easily produced the desired effect. The speculum was placed in water, and turned round by

the steam-engine, while the polisher had a horizontal motion given by the same means these two motions were the most apparent, but there were others, into the consideration of which we could not enter sufficiently briefly. The grinding-tool was made of iron, turned to the required shape in his lordship's workshop; it was then cut by grooves into octagonal-shaped pieces on the surface, and holes bored through it in different places to allow sand and water to run from the upper surface between it and the speculum: the supply of sand and water was constantly kept up. The entire weight of the grinder was not allowed to rest on the speculum; it was partly counterpoised by a weight hung to an attached lever. It required six weeks to grind it to a fair surface. The polishing generally requires only six hours. The same tool that grinds it is, for the purpose of polishing, covered over with pitch, on which crocus is spread: nothing else is necessary. The division of the tool into small parts on the surface by grooves is requisite for producing a good shape. If an even surface of pitch were used, the heat that is produced by the friction making the pitch soft, it would accumulate in some places more than others, and so destroy the right shape; but, when the surface is divided into those small portions, the pitch cannot be pushed to any distance from its original position, and, of course, the surface must be constantly true.

In the view of the tower of the workshop there is seen a long pole running up from the top. On the summit of this is a little crossbar, to which is attached a small dial of a watch. It is directly under this that the speculum was polished. The body of the tower serves as a tube, and the dial is reflected in the speculum below; the polishing is continued until the picture produced is absolutely perfect. When this process is finished, the speculum is ready for the tube; and such a tube as is prepared for it! a company of soldiers might go through their manoeuvres in it. It is fifty-two feet long, and seven in diameter. It was built in a long gallery, over a range of outhouses, and this had to be thrown down to take the leviathan away. It is made of wood, and hooped with iron. The mechanism by which it is suspended and moved is the result of deep calculation, and is not the least meritorious of Lord Rosse's works. When we see

this enormous instrument moved about and regulated by one man's arm, and placed in its position with more ease and certainty than a hand-instrument can be, we will then appreciate the plan and the mind that conceived it. We could not at all enter into a detailed account of the several pieces of the machinery: they would require a diligent study. The chief means employed is a large cast-iron hinge, which is attached to the bottom of the tube, and which allows it either to be elevated or depressed, or turned from side to side. This hinge is supported on and fixed into solid masonwork in the ground, and keeps one end of the tube stationary. The walls which support the machinery -a sketch of one of which we give-are built exactly in the meridional line, so that the telescope, lying between them, only takes in objects as they pass this line. They can be kept in the field of view for half an hour on each side of the meridian. The speculum is six feet in diameter, with a focal distance of fifty-two feet; its power of magnifying may be judged of by the fact, that a portion of the moon, the size of a common house, can be visible. Before being placed in the tube, it was fastened to what is called an equilibrium bed, a support made of triangular pieces of iron which have a motion among themselves, and so disposed that they adapt themselves to every change of state of the speculum produced by variation of temperature and other causes, and so prevent warping and its consequences. The iron pieces are lined with frieze and pitch.

His lordship has also erected an equatorial instrument. It is eighteen inches in diameter, the largest ever made, and, by its peculiar mechanism, the truest ever used. Sir James South laid out $35,000 in erecting one, and had to break it up afterward because it did not answer. Lord Rosse has been entirely successful. This instrument alone is a wonderful piece of work; but, taken in connection with all the rest, it is truly marvelous how much and how well one man has done.

Lord Rosse's pleasure-grounds are most elegantly and tastefully laid out. A large lake has been added to the other beauties of the place, and has given his lordship an opportunity of trying his skill as an engineer; the water for the lake being supplied from a distant part of a

river which runs through the demesne. As the bed of the river was low near where the lake was intended to be, an aqueduct was cut communicating with the river high up its source, and when it was brought to the required situation, a tunnel was sunk under the original bed of the river, and thus one stream runs over the other, both supplied by the same source. The tunnel answers its purpose completely. There is also a wire bridge of light and elegant appearance, suspended over the river close to the castle, which is likewise the produce of his lordship's workshop.

We have been tempted into a longer paper than we at first anticipated, and still we have left a great deal unsaid. We could with pleasure have given a more detailed account of his lordship's labors of his difficulties and successes in overcoming them-but these things would fill a volume, and would be obviously ill-adapted to a place like this.

It would be an injustice to the Countess of Rosse were this short notice of the demesne concluded without acknowledging the debt the people of Parsonstown owe to her. She has with most exquisite taste improved and made delightful the grounds about the castle, and freely opened them for their accommodation. She has made

the town the residence of all who can command the means, and the envy of those who cannot. She has raised the tone of its society; but she has done what reflects much more credit on her mind; she has taken the most lively interest in the poor, and is constantly improving and changing in order to afford them work. The lake was commenced solely to give them employment, and since then, hundreds have been daily hired to do what but for beneficence might well remain undone. The consequence of this conduct is, that she is universally esteemed and looked up to, and that her town is almost entirely free from the discontent and distress that are so rife in other places. The people are quiet and contented, and well disposed, and are as much indebted to the good sense that produced all this, as the world is to the talent that has astonished and is so likely to benefit it.

The town of Birr, or Parsonstown, is the prettiest inland town in Ireland. There are more private families living here than in any other town of the same size. There are public libraries and a mechanics' institute; first-rate markets, and everything that money can purchase. In fact, we think the town likely to progress rapidly, and we wish it God-speed.

A

THE MISSISSIPPI BUBBLE.

MID events like those recorded in our last article, which, humiliating though they be, partake largely of the ludicrous, others occurred of a more serious nature. Robberies in the streets were of daily occurrence, in consequence of the immense sums, in paper, which people carried about them. Assassinations were also frequent. One case in particular fixed the attention of the whole of France, not only on account of the enormity of the offense, but of the rank and high connections of the criminal.

The Count d'Horn, a younger brother of the Prince d'Horn, and related to the noble families of D'Aremberg, De Ligne, and De Montmorency, was a young man of dissipated character, and unprincipled as he was extravagant. In connection with two other young men as reckless as himself-named Mille, a Piedmontese captain, and one Destampes, or Lestang, a Fleming -he formed a design to rob a very rich broker, who was known, unfortunately for himself, to carry great sums about his person. The count pretended a desire to purchase of him a number of shares in the Company of the Indies, and for that purpose appointed to meet him in a cabaret, or low public-house, in the neighborhood of the Place Vendôme. The unsuspecting broker was punctual to his appointment; SO were the count and his two associates, whom he introduced as his particular friends. After a few moments' conversation, the count suddenly sprang upon his victim, and stabbed him three times in the breast with a poniard. The man fell heavily to the ground; and, while the count was employed in rifling his portfolio of bonds in the Mississippi and Indian schemes, to the amount of one hundred

thousand crowns, Mille, the Piedmontese, stabbed the unfortunate broker again and again, to make sure of his death. But the broker did not fall without a struggle, and his cries brought the people of the cabaret to his assistance. Lestang, the other assassin, who had been set to keep watch at a staircase, sprang from a window and escaped; but Mille and the Count d'Horn were seized in the very act.

This crime, committed in open day, and in so public a place as a cabaret, filled Paris with consternation. The trial of the assassins commenced on the following day; and the evidence being so clear, they were both found guilty, and condemned to be broken alive on the wheel. The noble relatives of the Count d'Horn absolutely blocked up the ante-chambers of the regent, praying for mercy on the misguided youth, and alleging that he was insane. The regent avoided them as long as possible, being determined that, in a case so atrocious, justice should take its course. But the importunity of these influential suitors was not to be overcome so silently; and they at last forced themselves into the presence of the regent, and prayed him to save their