AHNAPEE-AIGUES-MORTES

AHRENS, HEINRICH, born at Kniestedt, Hanover, July 14, 1808, was a German jurist and writer on philosophy and political science. He was educated at Göttingen, became a prominent AIGNAN, ÉTIENNE, a French publicist and contributor to the periodicals of the period, and littérateur, was born at Beaugency-sur-Loire in in 1839 professor of philosophy at Brussels. 1773. He became a member of the Academy in Later he held a professorship at Gratz, and finally 1814. He executed an excellent translation of became professor of practical philosophy and the Iliad into his native tongue, and wrote an impolitical science at Leipsic. He published psy-portant work entitled The Condition of the Proteschological and political treatises and a juristic tants in France. He died in 1824. encyclopædia. His Cours du Droit Naturel has been extensively translated, and is used as a basis for academical studies in South American countries. He died in Salzgitter, Prussia, Aug. 4, 1874.

AIGUILLON-AINSWORTH

Philip III in 1270, are of great archæological inter- | time until the Macdonald ministry went out of est. Wine and salt are its chief exports. Population 1891, 3,981.

power. Upon its return in 1878 he resumed his portfolio, resigning it two years later to become minister of inland revenue. He was lieutenantgovernor of Manitoba from 1882 to 88, retiring from public life with the expiration of that term of office.

AILANTHUS SILKWORM. See SILK, Vol. XXII, p. 60.

AILANTUS, a genus of trees of the family Simarubacea, natives of southeastern Asia. The best-known species is A. glandulosa, the "tree of heaven," or "Chinese sumach." It was introduced in the middle of the eighteenth century into France, Italy, Germany, Britain and the United States. It grows rapidly, has very long pinnate leaves, and is easily propagated by suckers and cuttings of the roots. In the United States it has become a pest in many places, owing to its rapid spreading and unpleasant odor. The wood is suited for cabinet-making, and the leaves afford It nutriment to a species of silkworm (Bombyx cynthia).

104

AINSWORTH-AIR-COMPRESSORS

Elkhorn and Missouri Valley railroad, 250 miles | rying power than by means of shafting, belts, etc. N. W. of Omaha. Population 1890, 733.

does, and a hundred minor purposes.

A few years ago the principal use of compressed AINSWORTH, WILLIAM FRANCIS, physician, air was for furnishing ventilation to mines, tunexplorer, and geologist; born at Exeter, England, nels and caissons. To-day it is used to drive in 1807. Studied medicine at Edinburgh, inter- street-cars, for package-delivery, in operating rupting his course for foreign travel. Having many kinds of machine-tools, the operation of received his degree, he traveled extensively in various small machines, the moving of liquids, in the East, becoming attached, in 1835, to an expe- stone-dressing, riveting, spraying-devices, paintdition to the Euphrates. Later, for the Geo-ing, discharging dynamite cartridges and torpegraphical Society, he traveled extensively in Asia Minor and Kurdistan. He was in England at the time (1832) of the appearance of cholera at Sunderland. His work On Pestilential Cholera is based upon observations made at that time. Has also published Researches in Assyria, Babylonia and Chaldea; Travels in the Track of the Ten Thousand Greeks, and numerous works of a similar nature. AINSWORTH, WILLIAM HARRISON, novelist; born at Manchester, England, Feb. 4, 1805; was educated for the legal profession, but while studying law in London he married a publisher's daughter (1826) and engaged in the publishing business. He became a distinguished author, his first hit being Rookwood (1834), with its characteristic story of Dick Turpin's Ride to York. He was the editor of Bentley's Miscellany; Ainsworth's Magazine; and the New Monthly, successively. He wrote 39 novels, 7 of them being illustrated by Cruikshank, and many of them originally appeared in the publications which he edited; Crichton (1837), Tower of London (1840); Tower Hill (1871); and Beau Nash (1880), being prominent among these. He died at Reigate, England, Jan. 3, 1882. AIR-BRAKE.

ments.

See BRAKE, in these Supple

AIR CAVITIES, often wrongly called air-cells. In plants they consist chiefly of cavities found in the ground-tissue, and are formed in various ways. In terrestrial plants they communicate with the exterior by means of the stomata, an interchange being thus established between the internal living cells and the outer air, which aids the passage of gases. They are specially developed, however, in aquatic plants, in which they may develop some member into a float.

AIR-COMPRESSORS, AND USES OF COMPRESSED AIR. The air-compressor is not a remarkable machine in its construction or details. It much resembles a steam-engine, only that it operates on a reverse principle, in that it condenses a fluid with a piston instead of using a condensed fluid to drive a piston. In practice it is usually a steam-engine having two tandem cylinders, one of which is a steam-cylinder driving a piston in the usual way. An extension of the same piston-rod enters the air-cylinder, where air is taken in and compressed by means of a valve-motion operating in a manner the reverse of the valve in the steam-cylinder.

It is the great number of new uses found for compressed air within the past 15 years that renders this subject of present interest. It is an old form of power, which came into extended use after electric-power had opened the way by demonstrating that there were better methods of car

Three railways in France and one in Switzerland are run by compressed-air power. One is running and others are projected in the United States. The plan is to make use of large storage-tanks placed under the bodies of the cars, and to use the pressure from them in cylinders, just as steam is used in the cylinder of a steam-engine. The difficulties of the system lie in the weight of the storage-tanks and the frequent charging required. Its advantages are the automobility of the car, freedom from noise, dirt and smoke, and correct operation regardless of weather. It has been proven that they may be run eight or nine miles on the level, but in practice it is found desirable to recharge the tanks about once in each mile and a half of travel. This is done at stations without any serious delay. The tanks are built of great strength, it being necessary to charge them with a pressure of about two thousand pounds to the square inch.

Pneumatic-delivery systems are in use in several of the large cities of Europe, and in New York, Philadelphia and Chicago. In some respects the Philadelphia plant is the most remarkable, making use of the largest pipes known to such service. It was installed in 1893, for the use of the postoffice, and the original line was half a mile long, but an extension is projected for the convenience of business firms. The tubes of this system are 61⁄2 inches in diameter, while most of the systems are from 1 to 3 inch tubes.

Many large machine-shops, railroad-shops, and the like, use compressed air to operate cranes, hoists and large machines generally. This form of power entails very little cost for the hours when the power is not wanted, and lends itself to a number of peculiar uses, such as the hoisting of oil from barrels by turning in a stream of air, the cleaning of steam-passages, the sweeping of floors, dusting of offices, etc. For cleaning dusty railway-cars it has no equal, being turned on with a hose, and driving out the dust just as readily as a pavement is washed with a hose and water.

The reliability of compressed air has led to its use in many mechanisms where absolute certainty of working is essential, as in the operation of switch and signal systems. Formerly such service was interfered with by the gathering of moisture in the pipes, which would freeze in cold weather, but various devices have been introduced that have overcome this danger.

For the operation of portable tools compressed air is obviously most convenient, since the tool can be connected by means of a flexible hose with its source of compressed air. It is largely used in

driving calking-tools for use in calking boilers, | water is prevented from rising in it. It is necestanks, and the like, the seams or joints of which have to be calked or hammered tight.

A stone-dressing tool was introduced in 1894, which is driven by compressed air, and which operates so satisfactorily that it is driving out hand-labor. Before its introduction it was found impracticable to dress stone down to a level by any machine, because the stone would usually fracture, as a result of the lack of intelligence on the part of the machine. With the compressed air stonedresser, however, it is necessary to dress only the edges of a stone by hand, the rest being reduced to a level surface by repeated rapid blows of the machine, guided by an attendant. The amount of stone removed at a blow is so perfectly regulable that even carving may be done with the machine, by the use of suitable reverse dies to guide the chisels.

Sprayed petroleum is much used as a boiler fuel in some localities, and compressed air is the motive power employed in the spraying. The amount of pressure can be adjusted by simply turning a cock, and it is easy to maintain a uniform heat with such a spray. The operations of tempering, welding, japanning, brazing, etc., demand a uniform heat, and therefore this aërated petroleum spray has come to be used in those lines of work.

sary to have, in some part of this caisson, a chamber to allow of the entrance and exit of men and materials. This small chamber is called an air-lock. When the outer door is closed after entrance, the air of the chamber is compressed before opening the inner one.

AIROLO, a town of south-central Switzerland, lying in the upper valley of the Ticino, and at the southern mouth of the great St. Gotthard railway tunnel. Lucerne is 38 miles N.W. of it, and Lake Como 43 miles S. E. It was the scene of a battle between the French and Russian forces on Sept. 13, 1799. Population, 3,674. AIR-PLANTS, a common name applied to aerophytes and epiphytes, which see, in these Supplements.

AIR-SACS, remarkable cavities connected with the respiratory system in birds. They are distributed along the inside of the whole cavity of the chest and abdomen. In birds of rapid flight and strong wing they often send prolongations into the bones, so reducing weight and aiding the bird in its flight. The sacs, or air-cells, in the lungs of the mammalia, into which the air is conveyed by minute ramifications of the windpipe, in order to be brought into contact with the blood distributed on their walls, are very small, being about only one thousandth part of an inch in diameter in man. In insects they form a spiral fiber within a membranous coat. The term is also used of spaces in the tissue of aquatic plants and of the bladders of seaweeds.

A new system of moving fluids by compressed air has been patented. It has been used to advantage in artesian wells, the method being to force the air down the well in a small side-tube, introducing it into the pipe proper of the well at the bottom, with an upward curve of the air-tube. The upward rush of the air, in its effort to reach the surface, results in its carrying the water up with it, and at the same time aërating and purifying the water, and leaving behind all objectionable mud and sand. This system is in use at 1823. This system is in use at Rockford, Illinois, and at Wayne, Pennsylvania. There are other places in the United States, as Little Rock, Arkansas, where the water-supply is purified by aëration, compressed-air plants being installed for that purpose.

Another interesting use of compressed air is in the manufacture of cellulose silk, which is made from wood-pulp by air-pressure. The pulp is forced out of minute holes, in a filament so tiny that six of them have to be twisted together to form a thread suitable for weaving.

AIRSHIPS. See AERONAUTICS, Vol. I, p. 185. AIRY, SIR GEORGE BIDDELL, English astronomer; born July 27, 1801, at Alnwick, in Northumberland; was educated at the Colchester Grammar School and Trinity College, graduating as senior wrangler from the latter institution in 1823. He was put in charge of the Cambridge Observatory (newly erected) in 1828, by virtue of his election to the Plumian professorship. Three years previously he devised a remedy for the optical malady in the human eye which afterward received the name of "astigmatism." In 1836 he succeeded Pond as astronomer royal at Greenwich, and was created Knight Commander of the Bath in 1872, being then president of the Royal Society. Later he conducted the astronomical observations preparatory to the definition of the boundary between the United States and Canada, and aided in tracing the Oregon boundary; established the system of correcting the disturbance of the compass in iron-built ships which is now universally adopted; was chairman of the commission appointed to superintend the construction of new standards of length and weight after the destruction by fire in 1834 of the AIR-LOCK. In the construction of bridge- former national standards. He attained great piers under water, hollow iron cylinders are used, fame by his researches in magnetism, meteorology, in which it is now the custom to use condensed photography, etc. His principal works are Graviair, the pressure usually not exceeding two tation; Mathematical Facts; Ipswich Lectures on Asatmospheres beyond ordinary atmospheric pres-tronomy; Treatise on Sound; Treatise on Partial Difsure. This iron shell is open at the bottom, but, ferential Equations; Vibrations; Treatise on Magnetbeing air-tight and water-tight at all other points, ism; and a Trigonometry. His last work was Notes

Under the most favorable conditions, compressed air can be delivered to customers, for use as power, at a cost of from thirty to fifty dollars per horse-power per year, and its use is steadily increasing. CHARLES H. COCHRANE. AIR-GUNS. See AIR-GUN, Vol. I, p. 428, and DYNAMITE GUNS, in these Supplements.

on the Earlier Hebrew Scriptures, published in 1876. He retired in 1881 on a pension of eleven hundred pounds, and died at Greenwich, Jan. 2, 1892. AIST, DIETMAR, one of the earliest of the German minnesingers; mentioned in writings between 1143 and 1170. By birth he was an Austrian. The few things written by him which are extant are in Lachmann and Haupt's Des Minnesangs Frühling.

AITCHISON, GEORGE, architect, was born in London, and graduated from the university of that city in 1850; studied architecture, and trav-| eled on the Continent from 1853 to 1855; became a fellow of the Royal Institute of British Architects in 1862, and associate of the Royal Acad- | emy in 1881. Mr. Aitchison has gained many medals, one of which was received at Chicago in 1893. His decorative designs at Kensington Palace, in Sir Frederic Leighton's house, and the Living Hall of the Goldsmiths' Company are highly regarded.

AITCHISON, JAMES EDWARD TIERNEY, Brigadier-Surgeon, was born in 1835; graduated M.D. at Edinburgh in 1856; entered Bengal medical department in 1858; attained his present rank in 1885, and retired in 1888. He acted as naturalist with the Afghan delimitation commission and as botanical collector throughout his connection with the army. He has written A Catalogue of the Plants of Punjaub and Sindh; Flora of the Thelum District; Flora of the Kuram Valley; and numerous other valuable additions to botanical knowledge. AITKEN, SIR WILLIAM, physician; born at Dundee, Scotland, April 23, 1825; was graduated from the University of Edinburgh, taking his medical degree in 1848; became demonstrator of anatomy at Glasgow, holding that office until April, 1855, when he volunteered for hospital service in the Crimean War, afterward becoming professor of pathology in the Army Medical School. In 1875 he was elected a fellow of the Royal Society, received the degree of LL.D. from the University of Edinburgh, and had knighthood conferred upon him in 1887, the year of the Queen's jubilee. He has been mainly occupied as a teacher and investigator in anatomy and pathology, being the author of On the Pathological Connections and Relations of Epidemic Disorders in Man and the Lower Animals, a Handbook of Science and Practice of Medicine, etc. Died June 25, 1892.

AJODHYA, an ancient city and former capital of Oudh, a north-central province of India, is situated on the right bank of the Gogra, in the vicinity of Faizabad, which is connected by rail with Lucknow, 75 miles to the west. Its site is said to have covered 96 square miles, now marked by heaps of ruins overgrown by jungle. modern town of Ajodhya has 7,500 inhabitants, nearly 100 temples, and the fair of Ramnami, which attracts half a million pilgrims yearly. See FAIZABAD, Vol. VIII, p. 855; OUDн, Vol. XVIII, p. 71.

The

AKBARPUR, a town of north-central India, in the British district of Cawnpur, and capital of a pergunnah of the same name. It is situated on the river Sarpe, a tributary of the Ganges, and is 100 miles E. of Lucknow, with which it is connected by rail. Population, 6,000. See CAWNPUR, Vol. V, p. 277.

AKEE, the Cupania sapida, a fruit-tree belonging to the family Sapindacea, a native of Guinea, but now distributed throughout the West Indies and South America. The black seeds are imbedded in a white, spongy aril, which, when cooked, is prized as food. It is also used as a remedy in diarrhoea, while the distilled water of the flowers is used as a cosmetic by the negro

women.

He

AKERMAN, AMOS T., a lawyer and politician, born in New Hampshire in 1823. Having practiced law in Georgia for several years before the war, his sympathies were with the South. advocated, however, the acceptance of the reconstruction measures of Congress, and was a prominent member of the Georgia convention of 1867 which formed the new state constitution. He was attorney-general under Grant (1870-72). Died at Cartersville, Georgia, Dec. 22, 1880.

He

AKERS, BENJAMIN PAUL, American sculptor, born in Saccarappa, Westbrook, Maine, July 10, 1825. He took lessons in Boston in modeling, his first work being a head of Christ, which was afterward put in marble. He located in Portland and made portrait busts of Henry W. Longfellow and of many other personages of note, as well as a head of Charlotte Corday and a bas-relief entitled Evening, both of which were masterpieces. studied a year in Florence, where he made several busts, and a Morning as a companion to Evening. While there he also put in marble several of his previous works. In the winter of 1853-54 he modeled his Benjamin in Egypt, and while in Washington the busts of many noted men of the time. In 1855 he traveled through Europe, makin two years, Peace; Una and the Lion; Girl; Pressing Grapes; Isaiah; Milton; Dead Pearl-Diver; Diana and Endymion; Saint Elizabeth of Hungary; Reindeer; and Schiller's Diver. | His constant labors on damp clay in a sunless studio impaired his health, and he died in Philadelphia, Pennsylvania, May 21, 1861.

AITKIN, capital of Aitkin County, in central Minnesota. It is 135 miles N. of Minneapolis and within 145 miles of the head of navigation on the Mississippi River; the Northern Pacific railroading, connects it with Duluth, which is 78 miles E. It is a lumber town, lying in the midst of a picturesque lake region. Population 1895, 1,670. AJALON, a town of the Levites, in the land of Dan in ancient Palestine. It was here that the battle between Joshua and the five Canaanitish kings took place, in which it is narrated that Joshua bade the sun and moon to stand still. The modern village of Yalo, 12 miles from Jerusalem, is believed to occupy its site.

AKHLAT, a town of Armenia, Asiatic Turkey; lies on the western shore of Lake Van, and is 240 miles S. E. of Trebizond and the Black Sea. The old city of Akhlat was the residence of many