in floral and in arabesque designs. For this purpose the brilliantly colored abalone shell is used with beautiful effect, especially when combined with white shell. Some very elaborate work of this nature is done. A mandolin recently exhibited in this country contained more than 2,000 pieces of four different kinds of shell, and 225 days' work were expended in cutting and finishing the pieces, the whole representing an investment of $1,500. Some years ago there was exhibited in New York a piano, the entire keyboard of which was of pearl. The body of the keys was of ordinary white shell and the flats and sharps were of green abalone, the effect being extremely rich and pleasing.

The most abundant shells in America are those of oysters and clams, especially the former. The product of these approximates 40,000,000 bushels annually and the purposes to which they are applied are numerous. The most important use is in road-making. At various points on the Atlantic seaboard, and particularly in the Chesapeake and the Delaware bay regions, many miles of good roads have been made of this material. It is estimated that 3,000 miles of roads on the Atlantic Coast have been surfaced with shells. Connecticut, Long Island, southern New Jersey, Delaware, Maryland, Virginia, North Carolina and Lousiana contain many excellent examples of oyster shell roads. To cover a road 16 feet wide to a depth of 15 inches in the middle and eight inches at the sides requires about 30,000 bushels of shells per mile, costing on an average of four cents per bushel or a total of $1,200 per mile. To keep such a road in good repair requires about 2,500 bushels of shells per mile annually at a cost of about $100. Though they constitute the cheapest and most convenient material in the sections where they are commonly used, shells are not wholly satisfactory for road material owing to their rapid wear and the spreading of objectionable lime dust.

Oyster shells have been largely employed as ballast for beds of railroads. While not nearly so durable or steady as rock, they answer the purpose fairly well and are the most convenient and economical material in many localities. Examples of their use for this purpose occur on many of the railroads in Maryland, Virginia and Lousiana.

Oyster shells have been extensively used as a source of lime, especially for agricultural purposes, as well as in masonry. Most of the brick buildings erected in colonial times were solidified with shell lime. Owing to its tendency to absorb moisture and thus make the houses damp its use for this purpose was abandoned soon after the discovery of limestone in abundance. The quantity of burned oyster shells spread on farming lands amounts to many thousands of tons annually. These shells are also crushed into small particles and fed to chickens to improve their digestion and their egg laying. This use is increasing in popularity. Oyster shells are also employed in the manufacture of certain special grades of steel owing to their large content of carbon.

A somewhat recent use for shells in America is for spreading on private oyster grounds for the purpose of obtaining a "set" of young oysters. When the extremely small oysters hatch from the floating eggs and sink to the

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bottom it is important that they find a clean substance for attachment, otherwise they are readily smothered. It is estimated that 4,000,000 bushels of oyster shells are used annually for this purpose, mostly in the waters of New York, Connecticut and Virginia. They are spread immediately before the spawning season, usually in June in the Chesapeake region and in July in Long Island Sound.

Several other varieties of shells are used for "spat collecting," especially "jingles" (Anomia ophippium), "quarterdecks" (Crepidula fornicata) and scallops (Pecten irradians). These are obtained mostly from Peconic Bay at the east end of Long Island where several hundred thousand bushels of mixed shells are dredged annually to be marketed in the oyster planting regions of New York and Connecticut. They are considered superior to oyster shells for "clutch," owing to the fact that they are smaller and only a few young oysters "set" on each, thus avoiding the crowding which occurs when large shells are used. Another reason for their preference is that they are easily broken and disintegrated and so do not encumber the ground after serving as "spat collectors."

Large quantities of shells are used for ornamental purposes. Especially prominent among these are the abalone or ear shells obtained from Califoria, Japan and various other countries. About 500 tons of abalone shells are gathered annually on the Pacific Coast of America, worth about $40,000. This product, however, is only one-fourth or one-third as large as it was 20 years ago. When cleaned and polished the highly iridescent green, red and pearly white colors are exquisite and make these shells beautifully ornamental. Much skill is exercised in polishing in order to produce the best effects. Some of the abalone shells are of such shape and coloring that it is possible in grinding to produce a perfect cross of black against a pearly white background; these meet with ready sale, the purchasers usually assuming that the cross appeared on the shell in

nature.

The large green conch or fountain shell obtained on the Florida coast, the West Indies, etc., is much used for ornament. The graceful curves and the delicate tints of lovely pink color make it one of the most attractive of all shells. It is much used in making brooches, earrings, etc., and in the form of beads in imitation of pink coral and pink pearls. Large quantities of conches have been pulverized and used in porcelain manufacture.

The pectens or scallop shells have long been admired owing to their beauty of form. During the Middle Ages pilgrims ornamented their clothing with them, as an indication, doubtless, of having crossed the sea to the Holy Shrine in Palestine, and for this reason they were known as "pilgrim shells." To commemorate that event they were preserved in the heraldic devices of many families whose ancestors had performed that journey. Scallop shells were formerly much used by cooks for holding foods, hence the name "scalloped oysters."

The popularity of shells for personal ornamentation has resulted in their use as currency or standard of value among many primitive peoples. A well-known example of this is the wampum of the North American aborigines,

made from the quahog or hard clam shell, so numerous on the Atlantic Coast. Somewhat less extensive was the use of the tooth shell or Dentalium on the northwest coast, and of the abalone on the California coast. Even at the present time in many parts of Africa and to a less extent in British India species of the cowry family are used as currency. In some seasons eight or 10 vessels carry cargoes of the money cowry (Cyprea moneta) to the west coast of Africa, where they are exchanged for palm oil and other products.

The window-glass shell (Placuna placenta), found in the Pacific and Indian oceans, and especially among the Philippine Islands, has an almost flat bivalve shell, six or eight inches in length. The inside of this shell is glazed over and has a subdued pearly lustre. It is so thin and transparent that print can be read through it, and it is used as a substitute for glass in windows, admitting a soft, mellow light into the room. It is commonly used in the Philippines in windows of residences, etc.

The giant clam (Tridacna) yields the largest and heaviest shells in existence single pairs weighing over 500 pounds in some instances. These are much used for ornaments, especially for fountain basins and for benetiers or holywater fonts. They are found in many tropical waters, and especially on the pearling grounds, where they are a source of danger to divers. A beautiful pair of these shells are used as benetiers in the church of Saint Sulpice in Paris. This pair is said to have been a gift of the republic of Venice to Francis I.

The most artistic use of shells is in the formation of cameos, which are cut from univalve shells made up of laminæ of different colors. The middle lamina, which is usually white, forms the body of the figure in basrelief, and the dark inner layer forms the ground. The outer or superficial layer is entirely removed, or it may be used to give a varied appearance to the surface of the design.

Of the several varieties of shells employed in cameo cutting, the black helmet (Cassis tuberosa) is the most valuable. This occurs in the West Indies and to a less extent on the American coast south of Cape Hatteras. It has a blackish inner coat and the cameo cut from it shows white upon the onyx ground, varying from dark claret to much lighter shades, producing effective results. This shell is ordinarily 12 inches in length, and usually five brooches of average size and several smaller articles may be cut from each one. The bull's mouth (Č. rufa) is also popular; it has a red inner coat and a sardonyx ground. The horned helmet (C. cornuta) gives white upon an orange yellow background. The lamina of this shell are apt to separate, making it disagreeable to work. The queen conch is also used to a considerable extent; the ground color is brilliant pink, which is somewhat evanescent on exposure to light. An attractive method of using this shell is to incise the bas-relief in the pink layer, using the white as the background, thus reversing the usual method.

Shell cameo figures consist of copies of antiques, original designs and portraits. Sometimes an entire shell- especially of the black helmet variety is used, and either a small figure is cut on the face of the shell or the entire surface is covered. In the latter case

the principal design is in the centre and around it are such minor designs as the fancy of the artist dictates. Some of these sell very high, and hundreds and even thousands of dollars are secured for a single carved shell. One exhibited in this country by a Naples artist represented two years' work. See CAMEOS.

SHELL CAMEOS. The ordinary medium used on which to carve cameos (see CAMEOS) was the kinds of quartz having layers of different colors, such as the onyx. They afforded a hard, durable substance which, when carved, maintained the sharpness of line. Shells such as those of the mollusks, conches, etc., were more or less utilized, probably on account of the ease of graving art effects on their softer body, but the ease of manipulation gained was at the cost of their durability. Few specimens of ancient shell cameos come down to us. Most of our earlier examples date from the 15th and 16th centuries. So the question whether ancient shell cameos were few or whether they are scarce now through being discarded when their beauty was marred by age remains open. An artistically carved Triducna squamata shell is in the British Museum, London, claimed to be of Phoenician workmanship (6th or 7th century B.C.).

History. By the 16th century Italian and French carvers vied with each other in producing artistic cameo effects on shells; there was a good demand for them. These Renaissance pieces are found on such helmet-shaped (cassis) conches as the Cassis rufa ("bull mouth"), Cassis tuberosa ("black helmet"), Cassis cornuta ("horned helmet"), also on the Strombus gigas ("pink queen's conch") and the Turbo. The pearl effect of the nacreous Melcagrina margaritifera and even the nautilus shell were utilized; in the former medium is a fine cameo portrait of Napoleon I in the British Museum. The Cypraea tigris ("tiger cowrie"), though small was used. The conch shells afforded two layers, white above and, beneath, pink, orange, yellow or gray; some give a reddish or "mahogany" ground. The gray appears to wear longest but most 16th century examples show deterioration. Shell cameos continued to be made in Italy and France till the end of the 17th century, when the demand appears to have died out. Early in the 19th century shell cameos were again in vogue for ladies' brooches and other personal adornment but the fashion fell off largely after the middle of the century only to be revived spasmodically. That the public has continued to appreciate fine effects in spite of reduced pecuniary valuations of mediocre pieces is well evidenced in the fact that so many examples of shell cameos still exist. The hot competition of connoisseurs in acquiring the very finest specimens is emphasized in the instance of the sale dispersing the Marlborough collection in 1899, when a shell Laocoon cameo cut by Fiamingo in the 17th century sold for £335.

Examples. Some of the finest specimens of shell cameo art to be found in the Morgan Collection donated to the American Museum of Natural History, New York City. Four magnificent examples are given in our illustrations; they are depictions of such subjects as a copy of Guido Reni's Aurora' on a Madagascar helmet shell (Cassis cameo); the intrusion of Actæon on Diana and her nymphs avenged,