Page:Popular Science Monthly Volume 46.djvu/734

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THE POPULAR SCIENCE MONTHLY.

large as a chestnut and free from any foreign substance is dropped through the tunnel, and that is lifted up at once. While the ants are still confused, and before any of them can reach the edge of the glass, it is covered with another square like it, which has been surrounded, a short distance from its edge, by a pad of putty. This confines the ants and prevents their being crushed. The two plates of glass are pressed together to within about the thickness of an ant's body, but closer on one side than on the other, so as to hold some tight and leave others free to take such positions as please them. On applying this box of ants to the ear as one would a watch, a regular buzzing may be heard like that of water boiling in an open vessel, and with it some very clear stridulations. The ants may be kept alive several hours and even days in this prison if it is not air-tight; and whenever the ants are excited the stridulations may be heard very numerous and intense. The stridulations are supposed to be produced by rubbing the rough scaly surface of the chitinous covering, which is described as looking, when seen in one direction under the microscope, like the teeth of a saw.

Ancient Use of Copper.—The range of metals and alloys at the disposition of the craftsman is really very wide, but he, nevertheless, Prof. Roberts-Austen says, restricts his efforts within narrow limits, and employs but few materials. The pure metals and fine wrought-iron work are seldom used, and have hardly any applications in art industries except when in union with other metals. The two series of alloys which have prominence in the history of art metal work are those of copper and tin, the bronzes, and the copper-zinc series—the brasses. Next in importance should come the lead-tin alloys—the pewters. Of the alloys of the precious metals, the gold-copper, the gold-silver, and the silver-copper are the most important. Taking the bronzes first, the important question at once suggests itself whether copper was employed before the general adoption of the alloy of copper and tin in industrial art. Berthelot has given us the analysis of a little Chaldean statuette of a god, now in the Louvre, which is considered to date from 4000 b. c., and it proved to be of metallic copper. There is also an analysis by Berthelot of the scepter of King Pepi I of the sixth Egyptian dynasty. This scepter, believed to be thirty-five hundred or four thousand years old, now in the British Museum, is of pure copper. From the anthropological point of view copper plays an essentially different part in prehistoric culture now from what was assigned to it a short time ago. Whereas it had been assumed that copper periods existed in Europe only in a few localities, finds of it have recently increased to such an extent that the assumption of a special copper age, which was prior to the bronze age and contemporary with the later stone age, seems to archaeologists now inevitable. Many of the objects found in Schliemann's first prehistoric city, Ilios, were of nearly pure copper. Other articles in the third city were of bronze. Our knowledge as to the first appearance of bronze has recently received new evidence in a rod found by Dr. W. Flinders Petrie at Meydum, of the fourth Egyptian dynasty, about 3700 b. c., which proves to be a bronze having about the ratio of nine parts of copper to one of tin, characteristic of far later and even of modern bronzes. Two works in the South Kensington Museum, one Etruscan and the other Greek, afford clear evidence of the introduction of tin into the art of those nations in the fifth century before Christ. The fact that the presence of lead in bronze enabled it to be more easily fused and also to assume a beautiful velvety-brown patina was, in the opinion of the author, recognized far earlier than has been supposed. Lead occurs in the analysis of a fragment of Greek bronze of a date about 450 b. c. The use of zinc is indicated in the descriptions in detail by Pliny of the various shades of color presented by bronze. The use of brass, which was common enough in Roman times, does not seem to have prevailed in England until William Austen, in 1460, made of it the magnificent monument of Richard Beauchamp, Earl of Warwick.

Preservation of Virginian Antiquities.—An Association for the Preservation of Virginian Antiquities was formed in 1888, at the suggestion of ladies of Williamsburg, and chose the wife of Governor Fitzhugh Lee as its first president. Mrs. Lee was succeeded at the expiration of Governor Lee's term by