him to a magnificent banquet, where he would be regaled with regal fare and royal honors. In the midst of the entertainment, however, Damocles happened to look upward, and perceived a naked sword suspended over his head by a single hair. The sight of this filled him with dismay, and taught him at what a sacrifice of mental peace and personal security the enjoyments and splendors of royalty may be purchased.

DAMODAR, dä-mō'där, a river of Bengal, in India, which after a southeast course flows into the Hugli, just above the James and Mary Sands and below Calcutta. A little below the mouth of its chief tributary, the Barákhar, which it receives from the north, the Dámodar becomes navigable. The valleys of these two streams contain the coal-fields which produce about four fifths of the whole amount of coal mined in British India. Length about 350 miles.

DAMON AND PHINTIAS (not PYTHIAS), two illustrious Syracusans, celebrated as models of constant friendship. Phintias had been unjustly condemned to death by Dionysius the Younger, tyrant of Sicily, but obtained permission to arrange his affairs in a neighboring place on condition that his friend should remain as a pledge of his return. Damon surrendered himself at the prison, ready to suffer death instead of Phintias if he did not return at a fixed time. Unexpected impediments detained him. Damon, still fully convinced of the faithfulness of his friend, was on the way to the place of exceution, and the people began to murmur and to pity his credulity, when Phintias suddenly rushed through the crowd into the arms of his friend. While they demanded each to die for the other, Dionysius himself approached, pardoned them and entreated them to admit him, a third in their friendship. Schiller has described this adventure in an excellent ballad, 'Die Burgschaft,' and it is the subject of a popular English drama.

DAMPER, a plate in an air-draft or flue, for the purpose of controlling the fire by regulating the area of the passage for the ingress or egress of air as the case may be. Dampers are of various forms. They are to the air-pipe or flue what the valve or faucet is to the duct for steam or liquids. The dampers of furnaces are either in the door of the ash-pit, to regulate the ingress of air, or in the course of or on top of the chimney, to close the egress of the volatile results of combustion. In the latter form they are used in almost all metallurgic furnaces.

In locomotive engines, a kind of iron venetian-blind, fixed to the smoke-box end of the boiler in front of the tubes; it is shut down when the engine is standing, and thus stops the draught and economizes fuel, but it is opened when the engine is running.

In pianofortes, certain movable parts, which are so arranged as to press upon the wires and check their vibration whenever the finger leaves the keyboard. Perfect damping is difficult to obtain, but when efficient it enhances brilliance of execution and distinctness of harmony in a composition.

DAMPIER, dam'pēr, Alfred, Anglo-Australian dramatist: b. London, 28 Feb. 1847. He began as an actor at Stratford-on-Avon and in

1873 he acted Mephistopheles in his own version of Goethe's 'Faust.' He visited the United States, Canada and South Africa. Returning to London he produced several of his own plays. From there he went to Australia and took over the Alexandra Theatre and renamed it the "Australia." Here many of his plays were produced, himself and his wife acting leading rôles in them. Later on his son and his daughter also played leading rôles in their father's productions. King'; Among his dramas are 'The Bush 'Waratha'; "Under the Southern Cross', and 'Robbery Under Arms. Some of his numerous dramatic pieces were written in collaboration with Garnet Walch and W. L. Lincoln.

DAMPIER, William, English navigator: b. East Coker, Somerset, June 1652; d. London, March 1715. In 1673 he served in the Dutch War and subsequently engaged in a band of privateers, as they called themselves, although in reality pirates, with whom he roved on the Peruvian coasts. Dampier, wishing to obtain some knowledge of the northern coast of Mexico, joined the crew of Captain Swan, who cruised in the hopes of meeting the annual royal Manila ship, which, however, escaped them. Swan and Dampier were resolved to steer for the East Indies and they accordingly crossed the Pacific and after various adventures Dampier and others were left ashore on Nicobar Island. After making several trading voyages in the Eastern seas he entered as a gunner in the fort at Bencoolen. Upon this coast he remained until 1691, when he found means to return home. In 1697 he published an account of his voyage round the world, which had a great success and was supplemented by a second volume in 1699. He now obtained command of a ship in the king's service fitted out for a voyage of discovery. In this he made important explorations on the coasts of Australia and New Guinea, giving his name to Dampier Archipelago and Strait. His last two trips around the world 1703-07 and 1708-11 were commercial enterprises. Dampier's writings include A Voyage Round the World' (1697); A Discourse of Winds) (1609); Vindication of the Voyage to the South Sea' (1707); Voyages to the Bay of Campeachy) (1729). They bear all the marks of fidelity; and the nautical remarks display much professional and even philosophical knowledge. His observations on natural objects are also extremely clear and particular.

DAMPIER, the name of several places in Australasia: (1) Dampier Archipelago, a cluster of about 20 small rocky islands off the northwest coast of Australia, in lat. 21° S., and long. 117° E., divided by the Mermaid Strait in two groups; in the east is Rosemary, the largest island. (2) Dampier Island, off the northeast coast of New Guinea, with a volcano about 5,250 feet high. (3) Dampier's Land, a penin sula of western Australia, fertile and well watered, lying between King Sound and the Indian Ocean. (4) Dampier Strait, separating Neupommern (off Papua) from Rock Island. (5) Dampier Strait, separating the island of Waigiu from the northwest extremity of New Guinea, the safest and easiest passage between the Indian and Pacific oceans. It is 70 miles long and 35 miles wide.

DAMPING-OFF, the rotting of seedlings and cuttings in the seed-bed and the cutting bench, usually just above the surface of the soil The immediate cause is a soil fungus (usually Artotragus or Pythium debaryanum, though other fungi may produce the same effect) which feeds upon decaying organic matter until it obtains a favorable opportunity for attacking a living host. This opportunity is generally afforded by a weakened condition of the seedlings or cuttings due to a more or less stagnated atmosphere highly charged with moisture and of rather high temperature. The fungus gains entrance to the weakened stems which soon turn brown or black. The foliage quickly becomes infested and sometimes in a single night a whole seedbed or bench full of cuttings may become a rotting mass with no healthy plants left. With careful management the trouble can be avoided. The propagating medium should be clean, sharp sand, which should be thoroughly drenched when the bed is watered, the excess water pass ing quickly away in perfect drainage. The bed should never be allowed to become dry. In short, both seedlings and cuttings should be kept growing steadily and sturdily. The drenching washes the spores of the fungus down through the sand. Should a bed become infested the healthy plants should at once be transferred singly and with as little soil as possible to fresh quarters. Neither freezing nor drying the soil will kill the fungus, which can live for months when growth is impossible. Sterilizing the sand or soil with steam is sometimes resorted to, the sand being heated for several hours. Less frequently plants in the open air” are attacked. In the greenhouse and nursery experience in management will count for much.

DAMPS, certain deleterious gases which are released in mines. See AFTER-DAMP; CHOKEDAMP; FIRE-DAMP; LAMP, SAFETY LAMP,

DAMROSCH, däm'rosh, Frank Heins, American musician: b. Breslau, Prussia, 22 June 1859. He was trained, by his father, Leopold (q.v.), and in 1882 became conductor of the Denver Chorus Club and supervisor of music in the public schools of that city. He was chorus master at the Metropolitan Opera House, New York, from 1885 to 1891, and in 1892 organized the People's Singing Classes. From 1897 to 1905 supervisor of music in the public schools of New York; from 1898 to 1911 director of the Oratorio Society; since 1893 director of the Musical Art Society; since 1905 director of the Institute of Musical Art.

DAMROSCH, Leopold, German musician: b. Posen, Prussia, 22 Oct. 1832; d. New York, 15 Feb. 1885. He was graduated from the Univer sity of Berlin, and began the practice of medicine; but his love for music predominated, and in 1864 he gave up his medical profession and started on a tour as violinist. He met with great success and on his return to Posen was appointed musical director at the Stadt Theatre. He subsequently held a similar post in Breslau. Coming to the United States, he was made leader of the Arion Society in New York, founded the Oratorio and Symphony societies of that city and was successful in introducing German opera at the Metropolitan Opera House. He published several cantatas, over tures and numerous pieces for the violin.

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DAMROSCH, Walter Johannes, American musician: b. Breslau, Prussia, 30 Jan. 1862. He is a son of Leopold Damrosch (q.v.), and has been a resident in the United States since 1871.) He inherited the musical talent of his father, i and succeeded him in his enterprises. In 1894 he founded the Damrosch Opera Company for the production of Wagner. Since 1903 he has been director of the New York Symphony Orchestra which he also reorganized. He is the special exponent of the Wagnerian schooli of music, and has conducted operatic performances in all the large cities, proving himself a most acceptable leader. His compositions include an opera founded on Hawthorne's tale of "The Scarlet Letter with which he toured the United States (1894); Manila Te Deum,' a sonata produced in New York (1898);: (Cyrano de Bergerac, an opera in four acts (1913); and the incidental music for 'Medea', and Iphigenia' for the Greek Theatre at Berkeley, Cal., in 1915. In 1914, Columbia University conferred on him the degree of doctor of music.

DAMS. To dam (originally, to stop up). is to obstruct or restrain the flow of a liquid. In engineering, a dam is a barrier to constrain or keep back a body of water. Dams vary in structure as widely as the physical character of their sites, the purposes for which they are constructed and the materials used. Every dam is, in a sense, a special adaptation, and may only be classified by referring it to some more or less varying type,

The art of dam building is coeval with civilization when the stream from the mountains, spending itself in the arid plain, was diverted for irrigation. The gardens and the waterwheels of Damascus are back of history. The Nile Valley, the Euphrates-Tigris plain, the Oxus and Jaxartes, and much of India, developed civilization in the application of the waters to the land, and this will be the history of their restoration. It was a time of mighty endeavor in hydraulic engineering, little understood in humid lands, demanding a high social organization and a closely knit state. Cyrus turned the Euphrates from Babylon and an empire fell and rose. Lake Moeris regulated the floods of the Nile in the days of Joseph, and its operation is credited with the seven fat and the seven lean years by some antiquarians; and Bahr Jussuf (meaning, the water carrier) still, leads to the Fayum basin. Modern Egypt has built the barrage across the Rosetta and Damietta mouths of the Nile for the continuous irrigation of the delta, and the dam at Assouan puts under service more than 6,000,000 acres of new lands, nearly doubling agricultural Egypt.

The old Hindu anicut turned the flow of, formidable rivers into irrigation canals, and as a rock-fill with long paved slope and an apron down stream, it serves the engineers of India to-day. The ancient "tanks" of India are natural depressions closed by a bank of earth, sometimes of great height and miles in length, formed probably by basket carriage and consolidated by tramping. The Veranum Tank still in use has a water area of 35 square miles held by a dam of clayey earth 12 miles long.

The protection of lands against flood by embankments, levees or dykes, belongs to primitive times. Along the Yellow River

("China's Sorrow") the Chinese built levees in double line with cross-banks, so that the failure of the front line at any point by undercutting or other cause would only inundate the check immediately behind. The Po and Adige of northern Italy were embanked in remote times and the history of these works is of great interest.

The basket-work dam of moderate height on alluvial streams was long since devised, and from this has evolved the modern bank protection of braided willow mattress in use on Western rivers. The primitive neighborhood grinding-mill led the head-race up-stream to a dam of simple type.

The utilities widen in approaching the modern era. The stream flow of the growing season no longer suffices for the needs of irrigation and the surplus is impounded for larger areas and the time of need. The uncertain navigation of natural streams no longer satisfies commerce, aud canal systems follow with extensive storage and feed-water developments, and this again, with steam navigation, gives way to the direct improvement and the canalization of rivers by means of fixed or movable dams. Growing cities need water supplies, a demand now universal, and often extraordinary structures are required. Industries develop with the water power, the turbine makes higher heads available and changes the problem of dam construction for power purposes; and finally comes the electric generator and distant transmission of power to satisfy further demands.

The United States contains water power capable of enormous development, in fact, more than tenfold all the power now in use. Next to the land itself the running streams are the most valuable economic asset. The future may well see an era of dam and reservoir building, in the humid as well as in the arid regions, for the better equalization of the flow of streams, in the interest of navigation, the reclamation of alluvial lands, the development of water power, and the creation of fisheries. The acre of water may be made even more valuable than the acre of land.

Embankments. Embankments for restraining water are widely applied and have special names: as levees and dykes for protecting lands, banks forming canals, coffer-dams, reservoir embankments and the embankment with spillway adjunct for impounding water, the latter being called a dam.

The levee is built of the alluvium of river bottoms to restrain flood overflows. It is given sufficient freeboard above the greatest known flood, the top width is usually greater than the height and the side slopes are very flat, sometimes as low as five or six to one. The site is cleared of all humus and other vegetable matter and well broken, so as to bond the embankment to the natural ground, and all such material is excluded in forming the embankment. A "muck-ditch" is made when deemed necessary, and "buck-shot" or other water-tight material is puddled in and carried up into the embankment as a core.

Many hundred miles of levees have been built along the Mississippi River and its tributaries, some of them of very large proportions. When built according to the best practice, well seasoned and turfed over, failures are very rare, though floods often stand against them for

weeks and the material is comparatively mobile when saturated. Failures have been due to insufficient height and the chopping effect of waves, but especially to lack of maintenance and of care at critical periods. The crawfish burrowed through at the turf line when its removal was omitted, and the board fences built in the levee to intercept this pest, decayed and weakened the levee. În northern latitudes the muskrat has also been a nuisance, as in the embankments of the reservoir system at the head-waters of the Mississippi River built for the purpose of increasing the low water flow.

Canals frequently skirt the sides of valleys or contour slopes, partially in excavation with part or full bank on the lower side. The material for forming such banks is generally far superior to that available for levee construction. The slopes are usually flat, from two to three on one, and a water-tight core or face is added in permeable ground, or the entire prism may be given a puddle lining when the percolation is liable to be serious. Sheet piling has been driven in such banks, but this divides the bank and is not now considered good practice. The unwatering of navigable canals in the winter time is also bad practice, as it subjects the inner face to frost action.

Canals are carried across water courses and valleys on supporting embankments, sometimes of great magnitude. Such embankments are given easy slopes and care exercised in forming a water-tight prism above, so as to avoid saturation and the resulting instability.

Ditches for irrigation and hydraulic mining sometimes reach the dignity of large canals, requiring care in the formation of banks. The soil of their location is usually of fine tilth with an admixture of adobe, and such channels generally "seal" quickly with the fine sediment carried in the flowing water of certain seasons.

The embankment used as a coffer-dam usually encloses some large site, as for the construction of a canal lock or for rock excavation in the dry, and is of a temporary character. Suitable material may be dumped from a trestle, the mass of material formed in water by dumping from a height being usually sufficient. In a notable case, a recent contract for a rock channel in the Saint Mary's River, a heavy embankment more than a mile long was formed of dredged material to a maximum height of 30 feet, and rock, estimated as wet excavation, was taken out in the dry at a large profit. No great care was taken in this embankment, except to provide suitable material and sufficient mass.

The reservoir embankment proper is usually for a storage or distributing reservoir, as for a municipal water supply. Such reservoirs are often 30 feet deep and the embankments are formed with great care from selected material placed in thin layers, watered and rolled. The inner face is lined and protected by a facewall, a pavement of brick, stone pitching, or even riprap in some large storage reservoirs. The height of the embankment varies with the supporting ground.

Earth Dams. The impounding embankment, or earth dam, is usually carried across some drainage line between steep valley slopes, so as to make a reservoir in the valley expanses above, and generally seeks to store a large proportion of the run-off. An ample spillway on