Page:The American Cyclopædia (1879) Volume IV.djvu/81

CASTING 73 are sometimes spoken of as the inventors of this art. It is difficult to believe that it was not introduced there at an earlier period, when it is certain that it was practised at Tyre, dis- tant but a few hundred miles by water, 400 years previously. However that may be, from the time of Theodorus it was carried to greater and greater perfection, until the time of Lysippus and Praxiteles, when bronze was moulded into forms of transcendent beauty. It is not unjust to assume that the world owes as much of its knowledge of casting metals to the old Greek sculptors as to any other source. The new art introduced by Rhoecus and Theodorus was transmitted to Crete, where two artists, Dipoenes and Scyllis, were distinguished as sculptors in bronze as well as marble. They carried the art to Sparta, which afterward produced many artists of her own, among whom was Gitiadas, also celebrated as an archi- tect, and who is said to have built the temple of Minerva Chalcicecus at Sparta, and cast a bronze statue of the goddess. The colossal statue of Apollo at Rhodes, made by the sculp- tor Chares, a pupil of Lysippus, who flourished about 290 B. 0., may be mentioned as an ex- ample of the magnitude to which the ancient Greeks were able to carry their works. This bronze statue was more than 105 ft. high, and, like modern statues, must have been cast in several pieces, which were afterward fastened together. The fragments into which it fell when destroyed by an earthquake 66 years after its erection lay on the ground 923 years, when they were sold by the Saracens to a Jew of Emesa, who loaded 900 camels with them. A fine example of bronze casting in the spirit of Lysippus is the beautiful statue of Mercury discovered at Herculaneum, and now in the FIG. 2. Bronze Statue of Mercury. museum at Naples. Whether it was cast in Italy or brought from Greece is uncertain. Church bells are said to have been introduced by Paulinus, bishop of Nola in Campania, about the year 400. They were probably in- troduced into England about the close of the 7th century. The great bell at Peking, cast in the feign of Yung-loh in the beginning of the 15th century, occupies a noteworthy place in the history of casting. It is 14J ft. hi height and 13 in diameter, and is estimated to weigh about 112,000 Ibs. It is covered both within and without with perfectly formed Chinese characters, embracing 87 sections of the sacred books of one of the religious orders. The greatest feat, however, that was ever performed in bell founding was the casting of the great bell of Moscow, which occurred in 1733 in the reign of the empress Anna. It is 19 ft. 3 in. in height and 60 ft. 9 in. in circumference, and weighs 443,772 Ibs. The appliances for melt- ing this great mass of over 200 tons of bronze metal must have been stupendous, and have required technical knowledge of no mean order. The process of casting varies with the kind of article to be produced and the material of which it is made. Iii casting a statue or a bust of plaster of Paris, where perfection of exte- rior form is alone sought, it is only necessary to pour an indefinite quantity of the fluid mixture of plaster and water into a hollow mould and take an impression of its internal surface. In casting a medallion or cameo it suffices to pour the liquid material over a one-sided? open mould to such a depth as may be required. But in the casting of statues in bronze, or in the casting of bells, of stoves, of cylinders, and of pieces of machinery, and all other articles that are required to have a definite thickness and weight, it is necessary that the moulds shall have two or more walls. The casting of statuary in plaster of Paris and in bronze will be treated of at the end of this article. Cast- ing or founding may be divided into : 1, prepar- ing a mould of the figure to be cast, which process usually includes the making of a pat- tern of such figure ; 2, the melting and reducing to the proper degree of fluidity of the metal ; and 3, the introduction of the molten metal into the cavity of the mould, and whatever manipulation may be necessary during the so- lidification and cooling. The mould may be made of metal, of stone, of plaster of Paris, of clay, of loam, or of sand. A metal mould may be formed either by excavating it with tools worked in a lathe or by the hand, or it may be cast in a similar manner to the article of which it is to form the mould. Small arti- cles of the more fusible metals, and of simple form, are usually cast in metal moulds which are composed of two or more parts held to- gether by hinges or pins. In using a metal mould, the molten metal, after being poured into it, may be allowed to solidify while cool- ing by the molecular attraction of its particles alone, or it may be so constructed that its con- tents are subjected to pressure during solidifi- cation. Bullets and small shot and printing types are examples of casting in metal moulds. Ingots of brass are examples of casting in stone