Popular Science Monthly/Volume 51/August 1897/Ivory: Its Sources and Uses
| IVORY: ITS SOURCES AND USES. |
By N. B. NELSON.
THOUGH an animal product, its combinations with wood, particularly ebony, from the earliest history, and the similarity of its uses and working in the way of carving, turning, veneering, and inlaying, make ivory an interesting material to joiners, decorators, and builders.
In texture, elasticity, hardness, peculiar markings or cloudings of the grain, and several other particulars, ivory is very like the harder woods, and, being of similar durability, is very suitable to "make up" in mosaics, inlaying, etc., with them, making a companion commodity.
Ivory is really dentine—that substance, not unlike bone, of which teeth principally consist. By usage it is restricted to the dentine of those teeth which are large enough for industrial purposes—viz., the tusks of the elephant, hippopotamus, walrus, narwhal, and some varieties of whales. These forms of ivory differ about as the hard woods differ: the elephant ivory, by its size and quality, is best suited for all purposes; that of the hippopotamus is harder and finer, but owing to its hollowness can only be used for small articles. The old Norsemen used extensively the tusks of the walrus, and when "whaling" was at its best the sperm whale was sought almost as much for the ivory as for the oil. It was the writer's fortune to examine a whale's tooth which was nine or ten inches in length and six or eight in circumference, and seemed solid ivory of a beautiful quality, but so hard as to defy every effort of its owner, who was an expert carver, spoiling, as he expressed it, his "tools and temper."
Ivory, consisting chemically of an organic matrix or growing element, phosphate and carbonate of lime, is permeated by numerous exceedingly fine canals, starting from the organic or pulp cavity and running generally outward to the circumference of the tusk. To the regularity and smallness of these canals ivory owes its elasticity, firmness, and fineness of grain; to their curvatures and eccentric direction—plainly visible in cross-cut sections—are due those beautiful cloudings and delicate markings which give value to, and readily distinguish the real from the imitated article.
Ivory is extremely hard and heavy—the very name, a Latin derivative from barrus, an elephant, so called from a Greek word meaning heavy. It is difficult to cut, requiring the sharpest and hardest of tools, but yields readily to the saw, the lathe, the file. Owing to its value, which is so constantly increasing that it now ranks with the "precious" substances, the greatest care is taken to avoid waste in manipulation. The cutting is effected with thin saws. Large plates of veneer have been obtained by the "reciprocating" saw, cutting a spiral shaving round the tusk. There is an account of one thus produced which was forty feet in length and twelve inches wide. Polishing is done by the use of various powders.
Ivory is dead pearly white in color, which sometimes changes with age and exposure to yellow, brown, or black. This natural whiteness is exquisitely delicate, and, as an enthusiast in ivories expresses it, "bears a great resemblance to the brightest tint of the human skin, which latter is the most beautiful hue in Nature." On account of the yellowing with age, there have been many recipes for restoring its whiteness, but none have proved satisfactory. A fortune is in store for the inventor or discoverer of the "happy medium." The opacity and elasticity of old ivory can be partially restored, at least to be useful for some purposes, by boiling in a solution of gelatin.
The existence of statues and of plaques of ivory larger than could be cut from any known tusk, render it probable that ancient workers possessed some method of bending or molding. It can be made flexible by a bath of phosphoric acid, but at the expense of many of its properties. It will also take a variety of dyes without interfering with its polish, particularly if the actual matrix or organic matter is stained.
The tusks of the elephant are an elongation of the upper incisor teeth, which may attain to enormous development; the largest are those of the extinct mammoth; some specimens have been found in Siberia more than twelve feet in length and two hundred pounds weight. There was a noted one of particularly fine quality, weighing one hundred and eighty-six pounds, that was cut up into piano keys.
Among the modern elephants the African possesses the largest tusks, often nine or ten feet in length, and weighing one hundred and sixty pounds each. A pair of African tusks was exhibited in London recently that weighed three hundred and twenty-five pounds, and measured eight and a half feet in length and twenty-two inches in circumference. Think of the muscular strength of head and neck necessary to support such a weight! The importance of these "ivories" in combat is evident by the dread of a "tusker" shown by elephants less favored. They are often broken in fighting, and always show marks of considerable wear. While even captive animals use them for a variety of purposes—e. g., a trained elephant when directed to pull a rope, will take it between his molar teeth and pass it over one of his tusks to get a good purchase. Nothing of less strength and elasticity than ivory could withstand the strain to which it is constantly exposed.
Foreign bodies, as bullets, arrowheads, or spear points, are often found imbedded in ivory. It is not a rare occurrence for the sportsman's bullet, or the native's spear, intended to pierce the elephant's brain, to penetrate the pulp cavity of the tusk and there become encysted or grown over with ivory and apparently have given the animal no trouble; but occasionally the viciousness of a "rogue," or the evident insanity of some unmanageable creature, has proved after death to have been caused by the suffering from inflammation and suppuration consequent upon the presence of a leaden ball in the "nerve of the tooth."
The best ivory is the African, and the finest quality from near the equator. Much of it is brought by natives from the interior to the coast and sold to Arab merchants, while many expeditions are organized by Europeans to go to the interior and collect the stores gathered by the native tribes. It is an extensive commerce. Four thousand pounds sterling, or twenty thousand dollars, is considered a good result for one season's expedition with one hundred and fifty men. Prices differ in different localities. The "portage," or distance from coast, size, condition, care in handling, and weight all affect price.
The African ivory trade is an ancient one, and in mediæval times Marco Polo, who lived from 1254 to 1324, speaks of the ivory traffic in Zanzibar being "astonishing in amount."
The tusks of the mammoth of northern Siberia, or the fossil supplies, are said to furnish almost the whole material of the Russian ivory workers. They are found in extraordinary abundance, and come principally from the neighborhood of the Lena and other arctic rivers and the coast islands. Mammoth tusks are more slender, more curved, and much larger in proportion than those of recent animals. Many have been found in the frozen morasses or in the solid ice, intact and in a beautiful state of preservation, having lain in their air-tight cases for many centuries.
Among the Scandinavians the tusks of the walrus have long been a source of ivory, and of very good quality too. The spirally twisted tusk of the narwhal is the desideratum of the Eskimo hunter. Asiatic ivory is from India and Ceylon elephants, which are rapidly disappearing. America has some fossil deposits and "glacial preserves" of mastodon ivories, but they are more sought for museums and antiquarian collections than for any commercial value.
The uses of ivory are exceedingly varied. The large cuttings are for veneer, plaques, panels, and portraits; then billiard balls, knife, cane, umbrella, and brush handles, piano keys, buttons, measuring rules, mathematical scales, statuettes, caskets, chessmen and draughtsmen, furniture decorations, and an endless variety of ornaments and works of art.
Ivory working is one of the oldest industries. Numerous references occur in the Old Testament which show that the material was regarded as of great value. It was an element in temple decoration, and is often mentioned among the presents to kings, who employed it for regal state. The ancient Egyptians and Assyrians used it extensively.
The excavations of Nineveh, a city that dates nearly 2000 years b. c., have supplied the British Museum with ivories of very great antiquity, many of them in good preservation, and many others tolerably well restored by boiling in gelatin; all show considerable artistic merit and mastery of the material.
Solomon had an ivory throne inlaid with gold—vide description in Chronicles; and the throne of Penelope, of about the same date, is said to have been of ivory and silver. Those ancient carvers attained a delicacy and artistic finish that our modern artists may well envy.
The later Greeks and Romans carried this gold·and·ivory and ebony·and·ivory work to a degree of splendor which seems incredible. From their extensive traffic with Persia and Egypt they obtained immense quantities of both Asiatic and African ivories. The Temple of Juno at Olympia contained, among many great works in ivory, the coffer of Cypselus, the bed, the discus, and the statues of Juno, the Hesperides, and Minerva.
The reputation of the great Phidias was based largely on his gold and ivory sculpture. The Minerva of the Parthenon, forty feet high, and the Olympic Jupiter, fifty-eight feet, evidently surpassed anything of the kind known to moderns. The pupils of Phidias made a number of those colossal images, in which the nude parts of the human figure were in ivory and the drapery in gold.
The Romans were equally extravagant; the gates of the Temple of Apollo, built by Augustus, were of this costly material. Charlemagne had two ivory gates of Byzantine workmanship. The episcopal chair of St. Vitalis, a work of the sixth century, is a fine specimen. Ivory seems to have become scarce in the twelfth century, and bone was largely used for carving, but during the middle ages ivory again became plentiful, and with the renaissance the art of carving reached perfection.
Florence, Flanders, and Germany were great centers. Cellini, Michael Angelo, Raphael, Dürer, and others tried the old-new art. In the seventeenth century there were many celebrated ivorists. Monks in cloisters frequently devoted a life to carving a crucifix; there are several specimens in different museums.
Schliemann, in his excavations at the supposed site of Troy, found many articles of ivory, useful and ornamental. The French town of Dieppe has had celebrated ivory factories since the fifteenth century, and is still extensively in the trade; but it is in the East, and especially in China, that ivory is most highly prized and worked into decorative forms.
No amount of care and patience is considered excessive among the Chinese in this work of ivory-cutting. This is evident in the extremely minute and delicate workmanship of their carved, lacelike trays, while their nests of concentric ivory balls are well known and are reckoned among the puzzles of industry.
The earliest recorded history—we might say prehistoric, the hieroglyphical—that has come down to us has been in carvings on ivory and bone. Long before metallurgy was known among the prehistoric races, carvings on reindeer horn and mammoth tusk, evidence the antiquity of the art. Fragments of horn and ivory, engraved with excellent pictures of animals, have been found in caves and beds of rivers and lakes. There are specimens in the British Museum, also in the Louvre, of the Egyptian skill in ivory carving, attributed to the age of Moses. In the latter collection are chairs or seats of the sixteenth century b. c. inlaid with ivory, and other pieces of the eleventh century b. c. We have already referred to the Nineveh ivories. Carving of the "precious substance" was extensively carried on at Constantinople during the middle ages. Combs, caskets, horns, boxes, etc., of carved ivory and bone, often set in precious stones, of the old Roman and Anglo-Saxon periods, are frequently found in tombs. Crucifixes and images of the Virgin and saints made in that age are often graceful and beautiful. The Chinese and Japanese are rival artists now in their peculiar minutiæ and detail.
Nothing is wasted in manipulating ivory; all dust, shavings, chips, and small pieces are utilized by being converted into gelatin, or ivory black, or artists' pigments; confectioners and chefs make use of ivory dust. Owing to the constantly increasing price, many attempts have been made to imitate ivory but with poor success. Billiard balls and other small articles have been made of celluloid, a combination of gun cotton, camphor, and ivory dust, but none have been satisfactory to the workman, whether carver, turner, or miniature painter.
There are not less than fourteen extinct but only two or three living species of elephants. Like the American buffalo, they are becoming less numerous every year. Though long-lived—some have in captivity lived over one hundred and fifty years—they propagate very slowly, the most slowly of any known animal; the period of gestation is twenty-two months, and but one at a birth, and they are gradually disappearing before the hunter. One writer states that England's imports of African ivory alone average in one year 15,550 hundredweight, worth from £600,000 to £750,000, or between, three and four million dollars, and predicts the certain decrease of supply and consequent increase of value of ivory.
