Scientific American — No. 1, January 1, 1870(txt+pdf+epub+mobi电子书下载)


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Scientific American — No. 1, January 1, 1870

Scientific American — No. 1, January 1, 1870试读:

Engines of the Spanish Gunboats.

In our description of these boats in No. 25, Vol. XXI., special mention was made of the compactness of the engines.

It has frequently been urged as an objection against the twin screw system that the double set of engines, four steam cylinders with duplicates of all the working parts called for on this system, render the whole too complicated and heavy for small vessels, preventing, at the same time, the application of surface condensation. In the engines of the Spanish gunboats, of which we annex an illustration from Engineering, the designer, Captain Ericsson, has overcome these objections by introducing a surface condenser, which, while it performs the function of condensing the steam to be returned to the boiler in the form of fresh water, serves as the principal support of the engines, dispensing entirely with the usual framework. Besides this expedient, each pair of cylinders have their slide frames for guiding the movements of the piston rods cast in one piece. Altogether the combination, is such that the total weight and space occupied by these novel twin screw engines do not exceed the ordinary single screw engines of equal power. Several improvements connected with the working gear have been introduced.ENGINES OF THE TWIN SCREW SPANISH GUNBOATS

The outer bearings of the propeller shafts, always difficult to regulate and keep in order on the twin screw system, are selfadjusting and accommodate themselves to every change of the direction of the shafts. This is effected by their being spherical externally, and resting in corresponding cavities in the stern braces or hangers. The spring bearings for supporting the middle of the shafts are also arranged on a similar self-adjusting principle.

The thrust bearing is of peculiar construction, the arrangement being such that the bearing surfaces remain in perfect contact however much the shaft may be out of line. The reversing gear likewise is quite peculiar, insuring complete control over the movement of the two propellers under all circumstances. It is claimed that these engines are the lightest and most compact yet constructed for twin screw vessels.

The Torpedo Boat Problem.

The Army and Navy Journal thinks the problem of a torpedo boat capable of firing rapidly and with certainty, has at length reached a satisfactory solution. It says:

"A boat has been completed which is proved by experiment to be faultless in machinery and arrangement. On the 2d of December, Secretary Robeson, Vice-Admiral Porter, and Commodore Case, Chief of the Bureau of Ordnance, went to the Navy Yard at Washington, to witness the experiment with this new engine of destruction. After examining the workings of the machinery, and the manner of firing, one of the destructives was put in the frame and the party proceeded to the shore to witness the result. A torpedo of only thirty-six pounds was first run out with rapidity and fired; but the result showed that this small amount of powder, even, would have been sufficient to destroy any ship, by lifting her out of the water and breaking her back, even if her bottom was not knocked out altogether. Mud and water were thrown up together, and the concussion was felt far up in the Navy Yard, the ground being shaken by the shock of the powder against the bed of the river. The concussion felt on board the torpedo-boat was not more than that caused by a wave striking a vessel at sea.

"Several torpedoes were fired from the vessel, the explosion of which the party witnessed on board, as they desired to ascertain for themselves the effect of the shock. The result seemed satisfactory, as no change whatever is contemplated in the machinery, which is very simple, and 'works to a charm.' The torpedo vessel is the Nina, a very strong iron boat of three hundred and fifty tuns burden, capable of crossing the ocean, and having a speed of seventeen knots an hour. She is not impervious to heavy shot, but can be made so, and is capable of resisting any ordinary projectile that could be brought to bear on her from the decks of a ship of war. Her decks will be made torpedo and shot-proof, and several arrangements will be applied, now that it is known that the torpedo system is a success. Such a vessel as the Nina, attacking an enemy's squadron on our coast some dark night, or entering an enemy's port, could destroy half the vessels in the harbor, and easily escape as few vessels could overtake her. Such a vessel could, for instance, enter the harbor of Havana, and destroy every vessel of war in the port, under cover of darkness. A squadron supplied with such boats to be used to attack, after the fight began, and the ships were enveloped in smoke, would have a most decided advantage against an enemy not thus armed for torpedo warfare. It is reported that our torpedo navy will consist of twenty vessels, none of which will have a less speed than twelve knots, and the fastest of them will go seventeen knots."

SUGAR MAKING IN LOUISIANA.

The New Orleans Times contains, in a late number, an account of the manufacture of sugar as conducted on the Poychas estate, from which we extract portions containing the essential particulars of cane sugar making as conducted in the southern portions of the United States.

"Reaching the Cane shed, the crop, dumped into piles, is received by a crowd of feeders, who place it (eight or ten stalks at a time) on the cane carrier. This is an elevator, on an endless band of wood and iron, which carries them to the second story, where the stalks drop between the rollers. An immense iron tank below, called a juice box, receives the liquid portion, and another elevator bears the bruised and broken fragments to the opposite side of the building, where they are dropped into the bagasse burner.

"This invention, at its introduction, caused more scientific inquiry and dispute, probably, than any other of the age, and settled beyond question the possibility of combustion, without the use of atmospheric air. The process consists in dropping the wet, spongy mass into a fire of wood or coal, and closing the furnace doors. The steam arising from the drying matter passes to a chamber in the rear, where, by the intense heat, it is decomposed. Oxygen and hydrogen (both strong combustibles) unite with the carbon, reaching there in the form of smoke, and a white heat is the result.

"Cane juice, as it escapes from the mill, could scarcely be considered inviting to either palate or vision. The sweet, slimy mass of fluid, covered with foam, and filled with sticks, has more the appearance of the water in a brewer's vat than anything which now suggests itself. A small furnace, containing a quantity of burning sulphur, sends through a tube a volume of its stifling fumes, and these, caught by jets of steam, thoroughly impregnate the contents of the juice box. Having received its first lesson in cleanliness, the liquid now rises through a tube to the series of clarifiers on the second floor. They are heated by a chain of steam pipes running along the bottom, and being filled, the juice slowly simmers Much of the foreign substance rises in a scum to the surface and is skimmed off by the sugar maker. It is further purified by the addition of Thomaston or what is called sugar lime. At one half a peck is considered sufficient for seven hundred and fifty gallons of juice, but much depends upon the quantity of saccharine matter it contains. Another set of pipes now permit the liquor to run into the evaporators, in the boiling room below. These are also heated by circles of steam pipes, and the liquid is first gently simmered, to enable any additional foreign substance to rise to the surface and be skimmed off.

"After that the steam is turned on fully, and the juice boils until it reaches the solidity of twenty-five degrees, as measured by the saccharometer. This point attained, more pipes conduct it to a series of square iron tanks called filterers. Each is provided with a false bottom, covered with thick woolen blankets, and through these the juice slowly drips into an immense iron vessel called a sirup tank.

"The process of cleaning has now been completed, and the sirup is pumped into the covered vessel previously alluded to, called the vacuum pan.

"This is also heated by layers of steam pipes, and here the liquor boils until the process of crystallization is completed. This end achieved, another conductor permits the substance to slowly descend to a large square iron tank, called a strike-pan. The process of emptying the vacuum pan is technically called a "strike." We now find a reddish brown substance, having somewhat the appearance of soft mortar.

"Men are at hand with square wooden boxes, and while the sugar is still warm, it is placed in rotary cylinders, protected on the inside by wire guards, called centrifugals.

"Placed on a horizontal, they revolve with a velocity which frequently reaches 1200 a minute. The damp, dingy looking pile instantly spreads, a broad circle of yellow is first visible on the inner rim of the machine, and this slowly whitening finally becomes a shining ring of snowy sugar. To effect this result requires the aid of nine steam boilers, three steam engines, a vacuum pan, three large evaporators, five clarifiers, five filters, an immense sirup tank, the juice box, mill, bagasse furnace, and fifteen coolers.

"With the engineers, sugar makers, firemen, and laborers, thirty-eight persons are constantly on duty in this sugar-house.

"Doubling this number, to give each the necessary rest, swells the gathering to seventy-six souls, who, during the grinding season, find employment at the sugar-house alone. This of course does not include the laborers employed in gathering and bringing in the crop, and the great number occupied in odd jobs and the extensive repairs which are constantly going on."

Sticking, or Court Plaster.

This plaster is well known from its general use and its healing properties. It is merely a kind of varnished silk, and its manufacture is very easy.

Bruise a sufficient quantity of isinglass, and let it soak in a little warm water for four-and-twenty hours; expose it to heat over the fire till the greater part of the water is dissipated, and supply its place by proof spirits of wine, which will combine with the isinglass. Strain the whole through a piece of open linen, taking care that the consistence of the mixture shall be such that, when cool, it may form a trembling jelly.

Extend the piece of black silk, of which you propose making your plaster, on a wooden frame, and fix it in that position by means of tacks or pack-thread. Then apply the isinglass (after it has been rendered liquid by a gentle heat) to the silk with a brush of fine hair (badgers' is the best). As soon as this first coating is dried, which will not be long, apply a second; and afterwards, if you wish the article to be very superior, a third. When the whole is dry, cover it with two or three coatings of the balsam of Peru.

This is the genuine court plaster. It is pliable, and never breaks, which is far from being the case with many of the spurious articles which are sold under that name. Indeed, this commodity is very frequently adulterated. A kind of plaster, with a very thick and brittle covering, is often sold for it. The manufacturers of this, instead of isinglass, use common glue, which is much cheaper; and cover the whole with spirit varnish, instead of balsam of Peru. This plaster cracks, and has none of the balsamic smell by which the genuine court plaster is distinguished. Another method of detecting the adulteration is to moisten it with your tongue on the side opposite to that which is varnished; and, if the plaster be genuine, it will adhere exceedingly well. The adulterated plaster is too hard for this; it will not stick, unless you moisten it on the varnished side.--The Painter, Gilder, and Varnisher's Companion.

AN IMPROVED HOISTING PULLEY WANTED.

A gentleman of this city has sent us the accompanying diagram of an improved hoisting pulley, for which he say she would be willing to pay any reasonable price provided he knew where to obtain it--the wheel, not the price. It is a pulley within a pulley, the friction of the outer one upon the inner one--the latter being held by a ratchet and pawl-acting as a brake in lowering weights, while both would turn together in elevating weights. The idea is rather an ingenious one, but we are confident our inventors can attain a like object by simpler means.

THE VACUUM METHOD OF MAKING ICE.--An ice and cold producing machine has been invented by Herr Franz Windhausen, Brunswick. The action of the machine is based on the principle of producing cold by the expansion of atmospheric air, which is accomplished by means of mechanical power. The machines require no chemicals, nothing being used in them but water and atmospheric air. They may be wrought by steam, water, or wind, and they produce from 100 to 1,000 lbs. of ice per hour, according to size, at a cost of from 2d. to 5d. per 100 lbs., this difference resulting from the varying prices of fuel and the mode of working chosen. One of their uses is to cool rooms, cellars, theaters, hospitals, compartments of ships, etc.--Builder.

FERDINAND DE LESSEPS--CHIEF PROMOTER OF THE SUEZ CANAL.

[From the Phrenological Journal.]

The scheme of re-opening the canal of the Pharaohs between the Mediterranean and Red seas, and thus connecting by a short cut across the Isthmus of Suez the commerce of Europe and Asia, though long entertained by the first Napoleon, may fairly be claimed for M. de Lesseps. His attention was doubtless first drawn to it by reading the memorable report of M. la Pére, who was employed by Bonaparte to make a survey in 1798. The credit of designing and executing the great work belongs alike to him. With the general plan, progress, and purpose of the Canal, the American reader has, during the past few months, been made tolerably familiar.

He is the son of Jean Baptiste Barthelemi, Baron de Lesseps, who was born at Cette, a French port on the Mediterranean, in 1765. Jean Baptiste was for five years French Vice-Consul at St. Petersburg. In 1785 he accompanied La Perouse on a voyage to Kamtchatka, whence he brought by land the papers containing a description of the expedition. In 1788 he was Consul at Kronstadt and St. Petersburg. From St. Petersburg he was called, in 1812, by the Emperor Napoleon, to Moscow, as intendant. From the latter city, in 1814, he proceeded to Lisbon, and was stationed there as Consul until 1823. He died at Paris, May 6, 1834.

Ferdinand, the subject of this sketch, was born at Versailles in 1805, and is consequently in his sixty-fourth year, though his appearance is that of a man little past the meridian of life. Early in life he evinced peculiar aptitude for the diplomatic career in which he has since distinguished himself--a career as varied and romantic as it is brilliant. In 1825 he was appointed attaché to the French Consulate at Lisbon. Two years later found him engaged in the Commercial Department of the Minister of Foreign Affairs. During the latter part of 1828 he was attaché to the Consul-General at Tunis; and in 1831 he was dispatched by his Government as Consul to Alexandria. Hard work and rapid promotion for le jeune diplomat! But the most eventful period of his long and wonderfully active career lay yet before him.

Seven years subsequent to his appointment at Alexandria, and consequently when he was in his thirty-fifth year, he was sent as Consul to Rotterdam. From Rotterdam he proceeded to Malaga in 1839, to negotiate in behalf of French commerce with the Spanish Government. In the latter part of the same year he was transferred to the Consulate at Barcelona, where during the two subsequent years he was especially active, and signally distinguished himself against the reign of Espartero. In 1844 we again find him in Alexandria, whither he was sent to take the place of Lavalette. But the time for the development of his great project had not yet come. He did not long remain in the Egyptian capital. Returning to his former position in Barcelona he was witness to some of the scenes of the revolution of February. In 1848 he was appointed French Minister at the court of Madrid. Remaining in the Spanish capital about a year, he returned to Paris immediately after the revolution of '48, and in May of the following year was dispatched as Envoy of the French Republic to the Republican Government of Mazzini at Rome, where he took a leading part in the abortive negotiations which preceded the restoration of the Pope by a French army.

In 1854 he received a commission from the Sociéte d'études du Canal de Suez at Paris to negotiate with Säid Pacha for the construction of the canal projected in 1816. Accordingly, toward the close of that year, we again find him on the Isthmus, preparing for his great work. This time he came to conquer. His mission was crowned with success, and the necessary concession made in November of that year. A palace and a retinue of servants were assigned to his use, and he was treated, as a guest of the Viceroy, with the utmost respect. Great opposition followed, especially from England; and it was not till January, 1856, that the second and fuller concession was granted by Säid Pacha, and a Compagnie International fully organized.

In 1858 M. Lesseps succeeded in raising two hundred millions of francs in France, and in 1859 he proceeded to Egypt and planted the Egyptian flag in the harbor of the ancient Pelusium, the great sea-port of Egypt thirty centuries ago, where Port Säid now stands. He laid, at the same time, the foundation of a lighthouse, and proudly proclaimed the work commenced. Fresh difficulties--chiefly of a political nature--interposed, but the indefatigable Lesseps never despaired. In 1859 he had the satisfaction of seeing his company and work placed upon a firm footing, though the final decision of the French Emperor was not given till July, 1864. From that time to the present hour the Canal has steadily progressed toward completion.

The personal appearance of M. de Lesseps is very striking. Though long past middle age, he has a fresh and even youthful appearance. Both face and figure are well preserved; his slightly curling gray hair sets off in pleasing contrast his bronzed yet clear complexion, his bright eye, and genial smile. He is somewhat over the medium stature, possessed of a compact and well-knit frame, carries his head erect, and moves about with a buoyancy and animation perfectly marvelous in one of his years and experience. His address is that of the well-bred, well-educated French gentleman that he is. His manner is winning, his voice clear and under most excellent control, as all those who have listened to his admirable lectures on the Canal at the late Paris Exposition cannot fail to remember. What is perhaps most remarkable in a man so bred and constituted, is that with great gentleness of speech and suavity of manner he combines a strength of will and fixity of purpose worthy of Napoleon or Caesar himself. Beneath that calm exterior lay a power which needed but the stimulus of a great idea to develop.

Though beset by difficulties, laughed at, and maligned, he has never for a moment swerved from his purpose or relaxed his efforts to accomplish it. Neither the sneers of Stevenson and his associate engineers, the heavy broadside of the "Thunderer," or the squibs of Punch, ever made any visible impression on the purpose or action of Lesseps.--"My purpose from the commencement was to have confidence," said he.

How bravely he has maintained his principle and redeemed his pledge let the ceremonies which marked the completion and inauguration of his great work tell--when sea sent greeting to sea; and let the keels of richly laden argosies from Cathay and from Ind, which plow the waters of the Canal, declare.

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