pyramids which mark, to the west, the extreme limits of the fertile land. Here, indeed, is a place for meditation, for nowhere do stones preach a more impressive sermon!

The quarries of Haggar Silsilis, in a wild mountainous country between Assuan and Edfu, are on a still grander scale. Passages as broad as streets, running on both sides between walls fifty or sixty feet high, now stretching straight forward, now curving, extend from the eastern bank of the river into the heart of the mountain, where spaces have been hollowed out large enough to embrace the Roman Colosseum! To the north numberless Cyclopean caverns have been hewn out, and enormous colonnades stretch along the foot of the mountain. The rough-hewn irregular roof rests upon immense square, or many-sided, pillars, frequently eighty or a hundred feet in circumference. Enormous blocks, already completely separated from the rock, rest on smaller ones, ready to be transported, while in other parts the labours of the quarrymen were suddenly arrested by the invasion of the foreign conqueror who put a stop to the dominion of the priests. The Bedouin, astonished at these vast works, so alien to his roving habits, exclaims at their aspect, with a wondering mien, Wallah! if these unbelievers had lived until now, they would have carried away the whole mountain and levelled it with the ground!'

Syracuse, the proud city that vied with Rome itself, and the remembrance of whose magnificence and glory, both in arts and arms, will live as long as classical literature, is now reduced to a heap of rubbish, for her remains deserve not the name of a city. But though even her ruins have mostly disappeared, etiam periere ruinæ,' yet the vast quarries which furnished the materials for her palaces and temples still bear witness to her ancient grandeur.

The Latomiæ of the Capuchins, thus named from a convent of that order, situated on the rock above, now form a noble subterranean garden, one of the most romantic and beautiful spots imaginable. Most of it is about one hundred feet below the level of the earth, and of an incredible extent. The whole is hewn out of a rock as hard as marble, composed of a concretion of shells, gravel, and other marine bodies.

The bottom of this immense quarry, from which pro

bably the greatest part of Syracuse was built, is now covered with an exceedingly rich soil; and as no wind from any point of the compass can touch it, it is filled with a great variety of the finest shrubs and fruit-trees, which bear with prodigal luxuriance, and are never blasted. The oranges, citrons, pomegranates, and figs are all of a remarkable size, and, frequently growing out of the hard rock, where there is no visible soil, exhibit a very uncommon and pleasing appearance. This quarry is the same that Cicero eloquently describes as the vast and magnificent work of the kings and tyrants of ancient Syracuse, hewn out of the rock to a prodigious depth. It also served as a prison for the Athenian soldiers that were made captives during the Peloponnesian war, and even now these vast excavations might be used for a similar purpose, as their high and overhanging walls forbid the possibility of escape, and ten men would be able to guard ten thousand without danger. Yet the genius of Euripides liberated many of his countrymen from this deep pit of bondage, for happening to sing a chorus of one of his immortal tragedies, they moved the tyrant to restore them to liberty, in honour of their illustrious fellow-citizen. Never has a more grateful offering been awarded to a poet's genius, and never has the magical power of the Muses celebrated a nobler triumph.

CHAPTER XXXIX.

PRECIOUS STONES.

Diamonds-Diamond Cutting-Rose Diamonds - Brilliants-The Diamond District in Brazil-Diamond Lavras-The great Russian Diamond-The Regent-The Koh-i-Noor-Its History-The Star of the South-Diamonds used for Industrial Purposes-The Oriental Ruby and Sapphire-The Spinel-The Chrysoberyl— The Emerald-The Beryl-The Zircon―The Topaz-The Oriental Turquoise— The Garnet-Lapis Lazuli - The Noble Opal-Inferior Precious Stones-The Agate-Cutters of Oberstein-Rock Crystal-The Rock-crystal Grotto of the Galenstock.

IN

N former ages superstition ascribed a strange mysterious power to precious stones. Gems of conspicuous size or lustre were supposed to confer health and prosperity on their owners, to preserve them in the midst of the most appalling dangers, or even to give them a command over the world of spirits.

The crucible of modern chemistry has, indeed, effectually dispelled these illusions of a poetic fancy; but the precious stones have lost nothing in value by their nature being better known. They are still the favourite and most costly ornaments of wealth and beauty, and they still deservedly rank among the wonders of creation. For surely no fabled talismanic virtues can be more worthy of admiration than that natural power which in the secret laboratories of the subterranean world has caused their atoms to unite in lustrous crystals, and imparted to such vulgar materials as carbon, clay, or sand the gorgeous reflections of the rainbow or the glorious colours of the setting sun.

The diamond, it is almost unnecessary to say, is the chief of precious stones, none other equalling it in brilliancy and refractive energy. Although generally colourless, like pure rock-crystal, yet it is also found of every variety of tint, from a roseate hue to crimson red, or from a pale yellow to dark

green and blue, or even black. Colourless diamonds are in general most highly esteemed, but coloured stones are sometimes of an exquisite beauty, and of corresponding value. Blue is an exceedingly rare colour, and one of this shade, the celebrated Hope diamond, which weighs forty-four and a half carats, and unites the charming colour of the sapphire with the prismatic fire of the diamond, is valued at 25,000l.

As the rough stones are rarely found with an even or transparent surface, the assistance of art is required to develop their full beauty. The diamond, being by far the hardest of all substances, can only be cut and polished by itself. Hence the lapidaries begin their operations by rubbing several diamonds against each other while rough, after having first glued them to the ends of two wooden blocks thick enough to be held in the hand. It is the powder thus rubbed off the stones, and received in a little box for the purpose, that serves to grind and polish them.

The process of diamond-cutting is effected by a horizontal iron plate of about ten inches' diameter, called a schyf or mill, which revolves from two thousand to three thousand times per minute, and is sprinkled over with diamond dust mixed with oil of olives. The diamond is fixed in a ball of pewter at the end of an arm resting upon the table on which the plate revolves; the other end, at which the ball containing the diamond is fixed, is pressed upon the wheel by movable weights at the discretion of the workman.

The method of cutting and polishing diamonds was unknown in Europe before the fifteenth century, but appears to have been practised long before in India, though in a rude manner. The original facetting of the Koh-i-Noor was the work of an unknown and prehistoric age.

The diamonds which were employed as ornaments before that period, as for instance the four large stones which enrich the clasp of the imperial mantle of Charlemagne, as now preserved in Paris, remained in their rough and uncut state. The invention is ascribed to Louis von Berguen, a native of Bruges, then the great emporium of Western trade and luxury, who in the year 1476 cut the fine diamond of Charles the Bold; and ever since that time Antwerp and Amsterdam *The carat is equal to 34 grains Troy weight.

COMBUSTIBILITY OF THE DIAMOND.

479

have maintained the first rank in the practice of an art which might be supposed to have a more appropriate seat in London or Paris, the centres of modern wealth and fashion.

Diamonds are generally cut either as rose diamonds or as brilliants. The rose diamond is flat beneath, while the upper face rises into a dome, and is cut into facets. The brilliant, which is always three times as thick as the rose diamond, is likewise cut into facets, but so as to form two pyramids rising from a common central base or girdle. Each pyramid is truncated at the top by a section parallel to the girdle, which cuts off of the whole height from the upper one, and from the lower one. The superior and larger plane thus produced is called the table; and the inferior and smaller one is called the collet. Although the rose diamond projects bright beams of light in more extensive proportion often than the brilliant, yet the latter shows an incomparably greater play, from the difference of its cutting. In executing this there are formed thirty-two faces of different figures, and inclined at different angles all round the table on the upper side of the stone, while on the under side twenty-four other faces are made round the small table. It is essential that the faces of the top and the bottom shall correspond together in sufficiently exact proportions to multiply the reflections and refractions, so as to produce the gorgeous display of prismatic colours which renders the brilliant so pre-eminently beautiful.

From the hardness of the diamond, its cutting is a very tedious and expensive operation, requiring more time in the proportion of fifty to one than the cutting of the sapphire, which comes next to it in hardness.

Experiment has determined that the diamond consists of pure carbon, so that the same substance which in its common black state is utterly worthless in very small quantities, becomes the most costly of precious stones, when it makes its appearance in the crystalline form. Already Newton, by observing the extraordinary refractive power of the diamond, had been led to place it among combustibles; but Cosmo III., Grand Duke of Tuscany, was the first who proved the truth of this bold conjecture by actual observation. He exposed diamonds to the heat of the powerful burning glass of Tschîrnhausen, and saw them vanish in a few moments into