sion of imperial sway. In the fourteenth and fifteenth centuries, when the Turks overran Asia Minor and southeastern Europe, and especially after they had captured Constantinople in 1453, partly in derision, and partly as an omen of future victories and the extension of the Mohammedan faith, they adopted the crescent as a national emblem, notwithstanding the fact that the use of images, symbols, religious, martial or civic decorations were prohibited by the Koran.

Crockery. The materials used in the manufacture of crockery are kaolin, pipe-clay, quartz or flint, and feldspar-the kaolin and quartz to give hardness, and the pipe-clay and feldspar to yield a flux sufficient to bind the masses firmly together. The materials are ground into a fine powder and then mixed with water in a machine called a "blunger," which is a box containing paddles worked very rapidly. When the matter has been thoroughly mixed it is drawn off and forced by a hydraulic pump through a series of sieves and then worked up in what is called a pug-mill, after which it is cut by a fine wire into rectangular blocks. These blocks are then molded into the shape of the article desired, some by the use of a lathe, and some by simply shaping them with the hands. The pieces are thus partially dried, turned on a lathe with a sharp tool to give them a uniform surface, dried slowly in a drying-room, then baked in an oven. In baking, the ware is kept at a white heat for thirty-six hours. The pieces are then glazed by being dipped in a mixture of ground feldspar, ground flint, sal soda, plastic clay and boracic acid, the whole pulverized and mixed with a small proportion of white lead and a little cobalt blue. This glaze is mixed with water, the articles are dipped in it one by one, receiving a deposit like a thin paste on the surface, which, when placed in the oven again, fuses and flows over it, making a coating of glassy smoothness. Fine white china or porcelain is of course made of finer material than crockery, but the process of manufacture is similar.

Cryolite is a snow-white mineral, partially transparent, of a vitreous luster and of brittle texture. It is so named from its fusibility in the flame of a candle. It is a compound of sodium, fluorine and aluminum, and is used for the preparation of the metal aluminum. It occurs in veins in gneiss with pyrites and galena, and has been found in western Greenland and at Miyask in the Ural Mountains. It is extensively employed in the United States in the manufacture of white porcelain glass, and also in the preparation of caustic soda.

Crystal Palace.-The present Crystal Palace is situated at Sydenham, seven and a half miles from London Bridge. The building was erected in 1854, chiefly from the materials of the building of the same name wherein was held the first great World's Fair in 1851-[see World's Fairs]-and is 1,600 feet long, 380 feet wide, and at the center transept 200 feet high. It is surrounded by beautiful and extensive parks and grounds, and has two tow

ers, from the top of which 10,000 square miles of England may be seen. There are also an opera-house and theatre, art galleries, two great concert-rooms, within the larger of which performances have taken place at which there were 5,000 vocalists and instru mentalists, a zoological collection, an exhibition department, and a large number of other attractions. The parks and gardens occupy nearly 200 acres, and are adorned with sculptures, stone balustrades, etc., and fountains which are perhaps the finest in the world. The Palace cost about $7,250,000.

Curacoa is a liqueur made either from the small Curacoa oranges and limes, or from their peel, by digesting in sweetened spirits, along with a little cinnamon, and often a little mace and cloves. The spirits used are generally reduced to about 56 under proof, and contain about 3 1-2 pounds of sugar per gallon. Curacoa is often colored by digesting in it for a week or ten days a little powdered Brazil-wood, and mellowing the color by means of burned sugar.

Curfew Bell.-The ringing of the curfew bell is commonly believed to have been introduced in England by William the Conqueror, who ordained, under severe penalties, that when the bell rang all lights and fires should be extinguished. In those days it was the custom to place the fire in a hole in the middle of the floor, and when the family retired for the night the fire was extinguished by covering it up; hence the term couvrefew, or curfew. At first the common hour was seven o'clock; then it was advanced to eight o'clock, and in some places to nine o'clock; while in Scotland ten o'clock was not an unusual hour. This law was abolished by Henry I in 1100; but the practice of tolling a bell at a certain hour in the evening was continued, and in fact is still extant in some places.

Cyclones, Cause of.-The theories regarding the cause of cyclones greatly conflict. Professor Tice of St. Louis, Mo., in describing the tornado which proved so destructive at Mansfield, Mo., a few years ago, stated that he considered it an electrical, and not, as commonly considered, a wind-storm. Among the evidence of the electrical nature of that storm he noted the fact that it destroyed every building which had a tin roof, or which had metal of any kind in its roof, and passed directly over several buildings with shingle roofs which were equally exposed. A mill, situated over a quarter of a mile away from the center of the cyclone had its iron chimney torn out and carried a long distance, while the mill itself suffered very little damage. The cupola of a schoolbuilding which had a tin roof was wrecked, but the building, which was roofed with shingles, was not injured. Even more remarkable, he considered, were the phenomena manifested in connection with trees and bushes. The bark was stripped from them on all sides, and the ends were not only denuded of their branches and leaves, but were rifted into fine fibers, so that they presented the appearance of little brooms. The active agency in such cases,

he insisted, was not wind, but electricity. General evidence of the electrical character of all tornadoes is found by Professor Tice in the fact that, as a rule, they follow railroads and water-courses, and either begin or expend their greatest energy upon them.

Cyclopean Architecture, the name which has come to be generally used for massive walls of large, irregular stones, unhewn and uncemented. The term originated in Greece, where structures of this kind were found, and were fabled to have been the work of the Cyclopes, or one-eyed giants.

Damascus Steel.-The skill of the Damascenes in the manufacture of steel became famous in Europe at the time of the crusades, but the secrets of their process have never been revealed. A Russian mining engineer, General Anosoff, by analysis and examination, however, succeeded in making steel that could scarcely be distinguished from it in appearance. The essential point of his process was melting the iron in crucibles with graphite and a small quantity of dolomite; but the details of working these materials with success were of course known only by himself, and the quality of the steel produced by the works since his death has very much deteriorated. An imitation of Damascus steel is also made in America and is often known by that name, though its proper appellation is damask steel, so called from the peculiar damask figures on its surface.

Danegelt, or Danegold, a tax which was originally levied upon the Saxons in England for purchasing peace from the Danes in the year 991; but it soon became a permanent tax upon landed property, and remained in force until 1173, when the last instance of its payment is recorded.

Dardanelles, The, are four castles or forts situated on opposite shores of the passage which joins the Sea of Marmora with the waters of the Egean Sea, but the name, by association, is also given to the channel of water between them. For many years the Turkish Government maintained that no foreign vessel of war should at any time be allowed to pass the Dardanelles forts. This restriction was recognized by Great Britain and France in 1809, and in consequence of which, in 1832-33 the British and French fleets were not permitted to enter the straits, though a Russian fleet from the Black Sea was anchored in the Bosphorus. This claim on the part of Turkey was fully recognized by all the great powers of Europe in 1841, and was reaffirmed in the Treaty of Paris in 1856. Two years later, however-November, 1858-the United States frigate Wabash passed the Dardanelles and anchored at Constantinople, the commanding officer claiming that the United States, not being a party to the Treaty of Paris, were not bound by its stipulations. Although no positive acknowledgment was made as to the correctness of this position, the vessel was received in a friendly manner by the Turkish Government. This clause of the Treaty of Paris was abrogated in 1876, and in times of peace there is now no restriction on the navigation of this strait. The two

castles at the entrance of the strait from the side of the Ægean Archipelago were built by Mohammed IV in 1659, and are still in excellent repair; but the other two castles are of much older construction, and though once very solidly built, now show signs of decay.

Dark as Egypt's Night."-The origin of this phrase is found in the tenth chapter of Exodus, the 21st, 22d and 23d verses: "And the Lord said unto Moses, stretch out thine hand toward heaven, that there may be darkness over the land of Egypt, even darkness that may be felt. And Moses stretched forth his hand toward heaven; and there was a thick darkness in all the land of Egypt for three days. They saw not one another, neither rose any from his place for three days; but all the children of Israel had light in their dwellings."

Dark Day, The.-So called on account of a remarkable darkness on that day, May 19, 1780, extending all over New England. In some places persons could not see to read common print in the open air for several hours together. Birds sang their evening song, disappeared and became silent; fowls went to roost; cattle sought the barn-yard, and candles were lighted in the houses. The obscuration began about ten o'clock in the morning and continued through the entire day, and was followed by an unusually intense degree of blackness during the ensuing night. The most intense and prolonged darkness, however, was confined to Massachusetts, especially to the eastern half of the State, when the people, believing that the end of all things had come, betook themselves to religious devotions. As to the explanation of this phenomenon, scientists have been much puzzled. It was plain from the falling of the barometer that the air was surcharged with heavy vapor. The darkness, then, it might be said, was only the result of a dense fog; but the question of the cause of so remarkable a fog was still unanswered. Large fires may have prevailed that spring in the forests of western New York and Pennsylvania -a region then an absolute wilderness-the smoke of which was borne through the upper regions of the atmosphere, to fall, when it came to a locality of less buoyant air, down to the lower strata. We say these fires may have recently preceded this day, and served as its sufficient cause, but we have only presumptive evidence that they did occur.

Dark Horse, The.-The custom of referring to the unexpected winner of a coveted honor as a "dark horse" probably originated from the practice of certain horse-jockeys who not infrequently, by coloring or painting some celebrated horse, were enabled to bring him into a race under another name, bet large sums of money upon him, and win the race. They were generally dark, and thus the term probably originated. The "dark horse in politics is applied to the successful nominee of a party who is little known or thought of as a nominee. President Hayes was a "dark horse."

Dauphin, at one time the title of the eldest son of the King of France. It was originally the title of the sovereign lords of the Province of Dauphiny. Humbert II, the last of these, dying childless, bequeathed his possessions to Charles of Valois, grandson of Philip VI, of France, on condition that the heir-apparent to the throne of France should bear the title of Dauphin of Vienne, and govern the province. Almost sovereign rights were conferred on the Dauphin by Louis IX, but these were gradually abridged by later kings, until Dauphiny was placed under the same laws as the rest of the kingdom, and the title became merely honorary. It was abolished altogether after the Revolution of 1830, Louis, son of Charles X, being the last who ever held the title.

Dead Sea, The, is situated in the southeast of Palestine, and is called by the Arabs Bahr Loot, or Sea of Lot. It is about 40 miles long, with an average breadth of 9 miles. Its depth varies considerably. It is fed by the Jordan from the north, and by many other streams, but has no apparent outlet, its superfluous water being supposed to be entirely carried off by evaporation. The north shores of the sea are marked by the blackened trunks and branches of trees which are encrusted with salt, as is everything that is exposed to the spray of this sea. On the southern shore is the remarkable mass of rock called Udsum (Sodom). It is a narrow, rugged ridge of hill extending five miles northwest, and consisting of rock-salt. To the north of Udsum, and at no great distance, is the supposed site of the ancient Sodom. On the borders of the Dead Sea a curious plant grows which yields fruit called the "Apple of Sodom," beautiful on the outside but bitter to the taste, and, when mature, filled with fiber and dust.

Deaf Mutes, Instruction of. It is recorded in history that a deaf mute was taught to pronounce words and sentences by an English bishop in the year 685, and from that time isolated cases of the same kind are mentioned till the latter part of the eighteenth century, when a school for the teaching of articulate speech to mutes was started in Germany. The method used is exceedingly simple, and consists merely in training the pupil, by imitating the position and action of the vocal organs of the teacher, to utter articulate sounds. Of late years another system has been introduced into English and American schools which has been found more generally successful than the lip-teaching of Germany. It is called visible speech, and was invented by A. Melville Bell, a professor of vocal physiology in England, about 1848. Mr. Bell's method consists of a species of phonetic writings, based not upon sound, but upon the action of the vocal organs in producing them. The characters of this alphabet reveal to the eye the position of these organs in the formation of any sound which can be produced by the human mouth. This alphabet was first applied in England to the instruction of deaf mutes in 1869, and it was introduced in America in 1872 by Professor Abraham Bell, a son of