fect heat engine.-See Tredgold, "Treatise on | Christian era. The earliest application of steam to turn the paddle wheel was anticipated by Roger Bacon. The attempt of Blasco de Garay in 1543, if it was made as asserted, is the earliest on record. Papin is said to have experimented with his engine in a model boat in 1707, on the Fulda at Cassel. Jonathan Hulls patented a marine steam engine Dec. 21, 1736, proposing to employ his vessel in towing. He published a descriptive pamphlet in 1737, containing a sketch (fig. 1) of a Newcomen engine, with a system of counterpoises, ropes, ratchets, and grooved wheels, giving a continuous motion. William Henry of Chester co., Pa., turned by a small engine. In 1789 a larger vessel, propelled by an engine of 12 horse power, attained a speed of 7 m. an hour. In 1801 Symington constructed for Lord Dundas a steamboat for towing on the canal, named the Charlotte Dundas, which was used successfully in 1802. It had a stern wheel driven by an engine, 22 in. in diameter of cylinder and of 4 ft. stroke. It drew vessels of 140 tons burden 3 m. an hour, but was laid up soon afterward in consequence of a fear that the banks of the canal might be seriously injured tried a model steamboat on the Conestoga | single paddle wheel placed between them and river in 1768. The count d'Auxiron, a French nobleman, assisted by M. Périer, made a similar attempt in 1774, and Périer repeated the experiment in 1775. The marquis de Jouffroy was engaged in the same work from 1776 to 1783, using a larger vessel and meeting with encouraging success. James Rumsey was engaged in experiments in the United States as early as 1784, and in 1786 drove a boat on the Potomac near Shepherdstown at the rate of 4 m. an hour by means of a water jet forced out at the stern. Rumsey subsequently went to England and continued his experiments on the Thames. (See RUMSEY, JAMES.) John Fitch worked at this problem at the same time with Rumsey, and had an experimental steamer on the Delaware in 1786. His propelling instruments were paddles suspended by the upper ends of their shafts and moved by a series of oranks. This boat (fig. 2) was 60 ft. long. Another vessel in 1790 made many trips on the Delaware, reaching an average speed of 74 m. an hour. It was laid up in 1792. In 1796 Fitch resumed his experiments at New York, using a screw. (See FITCH, JOHN.) In 1788 three Scotch gentlemen, Miller, Taylor, and Symington, obtained a speed of 5 m. an hour with a steamboat on Dalswinton loch. In this vessel two connected hulls were driven by a FIG. 2.-Fitch's Steamboat, 1786. by the waves. Robert Fulton, an American artist, and subsequently a civil engineer, built a steamboat on the Seine in 1803, assisted by Chancellor R. Livingston. (See FULTON, ROB-| ERT.) Fulton had known William Henry in the United States, and seems to have been familiar with the work of contemporary in FIG. 3.-Col. John Stevens's Steam Engine, Boiler, and Screws, 1804, ventors, and he had visited England, where he found others at work upon the same problem. In 1804 Col. John Stevens experimented with encouraging success with a small vessel driven by a high-pressure engine, a sectional boiler, and a single screw. He also tried twin screws, the steamboat having a length of 68 ft. and a breadth of 14 ft. This machinery (fig. 3) is retained in a good state of preservation at the Stevens institute of technology, Hoboken, N. J. Placed in a new hull on the Hudson in 1844, this engine produced a speed of 8 m. an hour. The experiments of Oliver Evans have been mentioned under STEAM CARRIAGE. Fulton, after studying the subject abroad, returned to the United States in 1806, and with Livingston had a boat built in which he placed machinery made by Boulton and Watt in England. The craft was 130 ft. long, of 18 ft. beam, 7 ft. depth, and 160 tons burden. The hull was built by Charles Brown of New York. The engine had FIG. 4.-Engine of the Clermont, 1807. a steam cylinder 24 in. in diameter and a stroke of 4 ft. The boiler was 20 ft. long, 7 ft. deep, and 8 ft. wide. The wheels were 15 ft. in diameter, with floats of 4 ft. length and 2 ft. dip. This steamboat, the Clermont, made a successful trip to Albany in 1807, leaving New York at 1 o'clock P. M. on Monday, Aug. 7, stopping at Livingston Manor (Clermont) from 1 o'clock Tuesday until 9 A. M. Wednesday, and reaching Albany at 5 P. M. on that day. The average speed was nearly 5 m. an hour. The return trip, on Thursday and Friday, occupied 30 hours, the rate of speed being 5 m. an hour. The Clermont, lengthened 10 ft., and with machinery slightly altered, made regular trips to Albany in 1808, and was the first steamboat ever made commercially successful. Almost simultaneously with Fulton's Clermont, Stevens brought out the Phoenix, a side-wheel steamer having hollow water lines; in the following year it was provided with feathering paddle wheels. This steamer could not ply on the Hudson, as Fulton and Livingston held a monopoly of the navigation of that river, and the Phoenix was taken by sea around to the Delaware river. This was the first sea voyage ever made by a steam vessel. From this time the steamboat was rapidly introduced. Fulton with his coadjutors placed a fleet upon the Hudson river and Long Island sound, and Stevens worked with his sons upon the Delaware and the Connecticut, and finally in the waters of New York also. In 1811 Fulton and Livingston began building steamers at Pittsburgh. In 1812 the Comet, built by Henry Bell, inaugurated regular steam navigation on the river Clyde in Scotland. This steamboat was 40 ft. long, 10 ft. wide, and of 25 tons burden. The engines, of three horse power, drove two pairs of paddle wheels. The speed attained was about 5 m. an hour. In 1825 James P. Allaire of New York built compound engines for the Henry Eckford, and subsequently constructed similar engines for several other steamers, of which the Sun made the trip from New York to Albany in 12 hours 18 minutes. Soon afterward Erastus W. Smith introduced this form of engine on the great lakes, and still later they were introduced into British steamers. The machinery of the steamer Buckeye State was constructed at the Allaire works, New York, in 1850, from the designs of John Baird and Erastus W. Smith, the latter being the designing and constructing engineer. The steamer was placed on the route between Buffalo, Cleveland, and Detroit in 1851, and gave most satisfactory results, consuming less than two thirds the fuel required by a similar vessel of the same line fitted with the single-cylinder engine. The steam cylinders of this engine were placed one within the other, the lowpressure exterior cylinder being annular. They were 37 and 80 in. in diameter respectively, and the stroke was 11 ft. Both pistons were connected to one cross head, and the general arrangement of the engine was similar to that of the common form of beam engine. The steam pressure was from 70 to 75 lbs., about the maximum pressure adopted a quarter of a century later on transatlantic lines. This steamer was of high speed as well as economical of fuel.-Ocean navigation by steam, begun by Stevens in 1808, was made an assured success by the voyage of the Savannah in 1819, from Savannah, Ga., to Russia via England. In this vessel both sails and steam were used. She returned to New York, direct from St. Petersburg, in 26 days. Between 1821 and 1825 John Babcock, Robert L. Thurston, and Capt. Northup ran steamers from Newport, R. I., to Provi- | 10 days. These vessels are now invariably dence and to New York. In 1825 the steamer fitted with the compound engine and surface Enterprise went to Calcutta from England, and condensers. The largest vessel yet constructed in 1836 it was proposed to establish lines of is the Great Eastern, fig. 5, begun in 1854 and steam vessels between New York and Liverpool. completed in 1859, by J. Scott Russell, on the In 1838 the Sirius, a ship of 700 tons and 250 Thames, England. This ship is 680 ft. long, horse power, sailed from Cork, April 4; and the Great Western, a comparatively powerful steamer of 1,340 tons, 236 ft. in length, with engines of 450 horse power, paddle wheels 28 ft. diameter and 10 ft. length of floats, sailed from Bristol April 8. Both vessels arrived at New York April 23, the Sirius in the morning and the Great Western in the afternoon. At this time Ericsson, Smith, and others were again experimenting with the screw, and Ericsson soon brought it into general use in the United States. His first boat was successful as a tugboat on the Thames in 1837. (See STEAM ENGINE.) The first naval screw vessel, the Archimedes, built for the British navy in 1840, was so perfectly successful that comparatively few paddle steamers were subsequently built. The earliest regular transatlantic line of steamers, the Cunard line, sent its first vessel, the Britannia, of 1,350 tons, from Liverpool, July 4, 1840. In 1847 Capt. R. B. Forbes took out the first transatlantic screw steamer, the Massachusetts, and introduced steam vessels into Chinese waters, sending out hulls and machinery from the United States in sailing vessels.Attempts have been made within a few years to revive the system of hydraulic propulsion first tried a century ago by Rumsey. Chain propulsion has in some instances proved very satisfactory. A chain or wire rope is laid in the bed of the river, or along the proposed route of the steamer, and passes over a drum worked by steam engines on the vessel, which is hauled along, taking in the chain at the bow and passing it out astern. In this arrangement loss by slip or oblique action is avoided, and a very satisfactory degree of economy is attained. Here, however, but little lateral movement of the vessel is permitted, and only one vessel can make use of the chain.-The most successful steam vessels in general use are the screw steamers of transoceanic lines. These are from 350 to 450 ft. long, usually propelled from 12 to 15 knots (14 to 173 m.) an hour, by engines of from 3,000 to 4,000 horse power, consuming from 70 to 100 tons of coal a day, and crossing the Atlantic in from 8 to FIG. 5.-Great Eastern. 83 ft. wide, 58 ft. deep, 28 ft. draught, and of 24,000 tons measurement. There are four paddlé and four screw engines, the former having steam cylinders 74 in. in diameter with 14 ft. stroke, the latter 84 in. in diameter and 4 ft. stroke. They are collectively of 10,000 actual horse power. The paddle wheels are 56 ft. in diameter, the screw 24 ft. The steam boilers supplying the paddle engines have 44,000 sq. ft. (more than an acre) of heating surface. The boilers supplying the screw engines are still larger. At 30 ft. draught this great vessel displaces 27,000 tons. The engines were designed to develop 10,000 horse power, driving the ship at the rate of 16 statute miles an hour. STEARIC ACID (Gr. ortap, tallow), a fatty acid obtained from mutton suet, and other fats that contain stearine, by saponifying suet and decomposing the hot solution of the soap with hydrochloric, or still better with tartaric acid. The oily acids are next submitted to pressure between hot plates, by which means a large portion of the oleic acid is separated; the solid residue is then to be purified by recrystallization from alcohol three or four times. Its formula is HC18H36O2. When recrystallized from ether, until the fusing point becomes constant at 159°, and slowly cooled, the acid forms beautiful colorless, transparent, rhombic plates; these melt into a colorless oil, tasteless and without odor, and when quickly cooled the substance concretes in a white crystalline mass, which is insoluble in water, but readily forms with hot alcohol a solution having acid reaction. It is the material of the so-called stearine candles. Stearic acid exists in fats in combination with glycerine, forming stearine, from which it is separated by saponification. | (See GLYCERINE.) It combines with numerous bases, and forms with them both normal and acid salts, called stearates. Stearate of soda is the basis of ordinary hard soap; stearate of lead is a constituent of lead plaster. STEARNS, a central co. of Minnesota, bounded E. by the Mississippi, and drained by Sauk river and lake; area, 1,379 sq. m.; pop. in 1870, 14,206. A portion of the county is prairie, but the W. part is hilly. There are numerous lakes and streams. It is traversed by the St. Paul and Pacific railroad. The chief productions in 1870 were 305,114 bushels of wheat, 78,627 of Indian corn, 447,193 of oats, 23,856 of barley, 120,865 of potatoes, 28,939 tons of hay, 17,701 lbs. of wool, and 323,085 of butter. There were 2,313 horses, 4,399 milch cows, 8,571 other cattle, 6,174 sheep, and 6,237 swine; 9 manufactories of carriages and wagons, 1 of agricultural implements, 4 of furniture, 7 breweries, 6 flour mills, and 5 saw mills. Capital, St. Cloud. STEATITE. See TALO. STEDMAN, Edmund Clarence, an American poet, born in Hartford, Conn., Oct. 8, 1833. He entered Yale college in 1849, was suspended in 1852, and did not return; but in 1871 the trustees restored him to his class and gave him the degree of A. M. After editing the "Norwich Tribune" and the "Winsted Herald," he settled in New York in 1855, and in 1859 became a writer for the "Tribune." In 1861 -2 he served as an army correspondent for the "World," and in 1863 he was private secretary to Attorney General Bates at Washington. In 1864 he became a stock broker in New York. He has published "Poems, Lyric and Idyllic" (1860); “ Alice of Monmouth, an Idyl of the Great War, and other Poems" (1864); "The Blameless Prince, and other Poems" (1869); "Complete Poems" (1873); and "Victorian Poets," a volume of critical studies (1875). and the largest amount of carbon which can exist in iron without destroying its malleability is about 2 per cent. Within these limits the compounds of iron and carbon possess the property of becoming soft when heated to redness and slowly cooled, and of becoming hard again when heated and quickly cooled. These processes of hardening and annealing may be repeated indefinitely, or until the carbon is burned out by the successive heatings. Iron with more carbon than 2 per cent. (say 2 to 5) is known as cast iron. It is more fusible than steel, but is not at all malleable, and while it may be hardened by sudden cooling, it is brittle and does not possess the resiliency or "spring" of steel. Soft or wrought iron has been until within the last 20 years worked by rolling or hammering when in a plastic condition at a red or white heat, owing to the impracticability of fusing pure iron. Steel was worked in the same manner as wrought iron until Huntsman succeeded in melting it in crucibles during the latter half of the last century, since when cast steel has replaced welded steel for most purposes, on account of its greater homogeneity, since all welded products consist of layers or fibres of metal separated by cinder, which, though it may be largely extruded by rolling or hammering, yet is always present to a sufficient extent to prevent the absolute contact of all the particles of metal. Since the idea of perfect homogeneity combined with malleability has so long been associated with our notions of steel, it was natural that when malleable iron, or iron low in carbon, was melted and cast in moulds, it should receive the name of steel without regard to the amount of carbon or the capacity for hardening. It is thus that the products of the Bessemer converter and the Siemens furnace have all been classed as steel, although the content of carbon may vary from 150 to 0:10 per cent.; and owing to the very large production of metal by these processes, far exceeding in amount ordinary cast steel, this classification has become well established in iron metallurgy. The uncertainty and confusion that has arisen from classing together products of widely different physical and chemical properties, has led to an active discussion of the definition and classification of steel. The classification of Greiner of Seraing is as follows: AMOUNT OF STEEL, a malleable compound of iron and carbon, which may be hardened and tempered. Considerable confusion in the use of the word has arisen in late years, owing to the introduction of improved metallurgical processes, whereby wrought or malleable iron may be melted and cast into ingots. These ingots, having the appearance of ordinary cast steel and some of its properties, have likewise received the name of steel, although they lack the capacity of hardening which hitherto was regarded as the essential characteristic of steel. Pure or wrought iron possesses a high degree of malleability and ductility, is difficultly fusible, may be welded at high temperature, but 0:45 to 0.55 below fusion, and is soft enough when cold to be readily wrought with tools. By the gradual addition of carbon to iron we notice an increase in fusibility, hardness, and resiliency, while malleability and ductility decrease. The smallest proportion of carbon which will distinctly produce these effects is about 0-25 per cent., 0 to 0.15 0.55 to 1.50 While the simplicity and convenience of this classification from a manufacturing point of view must be admitted, its adoption is opposed by Gruner and others on the ground that it takes no account of the capacity for hardening, -Among the elements other than carbon met | them a superiority over the carbon compounds with in steel are phosphorus, silicon, sulphur, and oxygen among the non-metals, and manganese, copper, tungsten, titanium, and chromium among the metals. Some of these are invariably present in the materials used for steel making, and are usually regarded as impurities in the steel, while others are added to produce certain specific effects. The modifications of the properties of steel by the above named elements have been already treated partially under IRON. Steel is more susceptible to the action of impurities than is wrought iron. This is especially true with regard to phosphorus and silicon, and is readily accounted for by the similarity of action of these substances with carbon. Recent experiments have shown that an amount of phosphorus which would be highly detrimental to steel containing say 0:50 per cent. of carbon, may be present with safety when the carbon is as low as 0.10 or 0.20 per cent., or in other words when the steel passes into soft iron. The effect of this formerly much dreaded enemy of iron and steel has been so thoroughly studied that "phosphorus steels," so called, are manufactured and sold. Phosphorus makes iron hard, brittle, and cold- | short (see IRON), and this is also true in a modified degree of carbon and silicon; hence, when two or all three are present together in iron, the effect is cumulative. The contradictory statements as to the maximum percentage of phosphorus that Bessemer metal will bear find here their explanation. It was formerly said that Bessemer steel with more than 0.05 per cent. of phosphorus was unfit for rails, but later experience has shown that if the amount of carbon does not exceed 0.15 per cent., phosphorus to the extent of 0.35 per cent. may exist without seriously impairing the strength and ductility of the metal. This fact, recently brought into prominence by the manufacture in France of phosphorus steel on a large scale, was recognized in this country as early as 1870. Samples of boiler plate and tough steel made at Trenton, N. J., by the Martin process, showed on analysis the following composition: for industrial applications. The effect of silicon on steel appears to be similar to that of carbon, as the general analogy of the two elements would suggest; but to produce a given degree of hardness, the amount of silicon necessary is very much greater than that of carbonthe reverse of the case with phosphorus. The most contradictory statements exist regarding the effect of silicon on steel. The best established data are summarized by Turner as follows: A small amount of silicon is not necessarily injurious to steel, and may be an advantage in those varieties which are to be used without hardening, and where there is no special demand for tenacity and strength. On the other hand, where steel must be hardened for use, as for tools, silicon can only be injurious, and that in proportion to the quantity present. This is one reason why Bessemer steel cannot generally be used for purposes requiring a fine, hard steel; for it is usually made from highly silicious pig iron. But some of the Swedish Bessemer steel, made from pure manganiferous pig iron low in silicon, approximates in quality to ordinary cast steel. A puddled steel made with the addition of a highly silicious iron ore has been brought into prominence under the name of "silicon steel;" but there is no evidence that it derives any of its properties from silicon, or indeed that there is any more silicon in it than in ordinary puddled steel. The effect of sulphur on steel is entirely different from that of the elements already mentioned. It makes it "red-short," that is, brittle when hot; but unlike phosphorus, it does not sensibly affect its malleability when cold. The largest amount of sulphur that steel will bear without serious impairment of its malleability is said to be about 0.10 per cent. Oxygen produces the same effect on homogeneous iron as sulphur, as might be inferred from the close chemical relations of the two elements. It can never exist in the harder steels prepared by fusion, for it would then combine with the carbon; but it is frequently met with in the Bessemer low steels and iron, and makes them red-short. Red-shortness, formerly ascribed exclusively to sulphur, has been found in very many instances to be due to oxygen. Consid0-160 0-120 0-120 0.125 0.120 erable importance has been attached to the 1 28 0.003 0.008 0.007 5 While it appears from the above that phosphorus may in a measure replace carbon in steel, the effect of these two substances is not identical, and the limit of rigidity is much sooner reached with the former than with the latter. The use of phosphorus steel is solely a question of economic advantage, since its manufacture permits the use of impure and consequently cheaper materials; but as far as is at present known, the compounds of iron and phosphorus possess no properties that give presence of nitrogen in steel, and Frémy considers it an essential ingredient. Numerous analyses do not support this view, and it is probable that its presence in steel is entirely accidental and due to the property which many metals possess of absorbing or occluding gases. -The compounds of iron with the metals, or the true alloys of iron, have not been as closely studied as its compounds with the non-metals, and but little can be said with precision of the physical characters of these alloys as such, or as modified by the presence of the non-metallic elements. The properties of iron are not as radically modified by the addition of small quantities of metals as is the case with the |