are then, by the same process, fastened on; and the whole being bound together with thick layers of twine, the boxes and their covers (which are yet in want of hinges, partitions, locks, &c.) are laid aside on a shelf to dry till the next day. When perfectly dry, the twine is taken off, the partitions are let in, and the boxes are handed over to a silversmith, who completes the work by adding the necessary little silver hinges and small silver knobs to the covers of the different small departments of the box, and the indispensable silver lock and key. This done, the boxes undergo a thorough scrubbing and polishing, and are then sent to a magazine, or storehouse, where they are carefully kept, wrapped up in silver paper, till a favourable opportunity occurs for disposing of them at a premium. The ladies' workboxes, in addition to all the foregoing processes, pass through the hands of a looking-glass manufacturer, who gives a finishing stroke to their elegance by the insertion of appropriately-sized glasses in the lids of the boxes, which are neatly framed in satinwood. The town of Vizagapatam is not so healthy by any means as the neighbouring station of Wattair, owing to its low and confined position : it is, nevertheless, an elysium in comparison to Massulipatam; and the "doctor," as the sea-breeze is facetiously called in India, which is a very regular and welcome visitor, sets in, generally, about two hours after midday. Tamul and Telagoo are the languages most in use, though Hindostanee will pass muster very well. The gardens in the suburbs yield abundant supply of fine fruits and vegetables, and there are a few decently-stocked shops, amongst which Hoffman's claimed the precedence. This man had, amongst other articles of use and curiosity, a queer old German clock, which literally astonished the weak minds of the natives and half-castes and Portuguese in the neighbourhood. It consisted of a sea of glass in perpetual motion, so long as the clock was going; a ship at anchor; a battery, on which a solitary soldier marched to and fro; a high watch-tower, whose diminutive clock indicated the hour; and a little boat, with four men and an officer, whose perpetual occupation was to row to and fro between the ship and the battery-a distance which occupied them an hour either way. When the boat arrived at the battery the hour struck, the soldier presented arins, and a savage little band of music rushed out, blowing defiance at the ship and the boat to the tune of "Blow, warder, blow!" The moment the music finished, the musicians retreated precipitately backwards into the watch-tower, and the boat, which pulled in a circle, was returning by rather a circuitous route to the ship: the instant it got alongside the tower clock struck the hour, but no ruffians rushed out this time, it was the ship's turn to do something wonderful; up flew a red flag with Death's head and marrowbones to the gaff, and six little bullets as. big as peas, supposed to be fired from the pirates' gun, were shot by some skilful mechanism against the battery, which they all hit at the same instant, and so disappeared beneath a yawning glassy wave, which on close observation we found to be the only one stationary on the whole sea. It was certainly a very ingeniously-managed toy; and old H., who persuaded the people that he had made it himself, was regarded as a regular pishash by all the native inhabitants of Vizagapatam. * * Devil. ON GEMS AND PRECIOUS STONES.* THE display of gems in the Great Exhibition was one of unexampled magnificence. To give a mere catalogue of its riches would occupy more than the hour appropriated to this lecture. My object will therefore be, to describe separately a few of the principal specimens there exhibited, premising only such observations on their history and distinctive characters as may be easily followed by those who are not acquainted with the technicalities of the subject; and then, in a general view of the remaining gems, to intersperse some remarks on the physical characters of each, and to conclude with an account of the principal localities in Brazil where by far the larger proportion of the diamonds of commerce are found; an exemplification of the mode of valuing them, the means of distinguishing the artificial from the genuine, &c. From the earliest ages of the world's history the mineral treasures of the earth appear to have been, to a certain extent, known to man. In the second chapter of Genesis we read of the land of Havilah," where there is gold," and where also is "bdellium and the onyx stone' (Gen. ii. 12); and in the Book of Exodus is a particular description of the breastplate of Aaron, enriched with many precious stones. These are distinguished as sardius (or ruby), topaz, carbuncle, emerald, sapphire, diamond, ligure, agate, amethyst, beryl, onyx, and jasper (Exod. xxviii. 17-19); but probably these names are now differently applied. The way in which precious stones are referred to in the Holy Scriptures, as well as in other ancient records, proves that they were always highly esteemed, either for their scarcity or their beauty, and were reckoned among the most valuable productions of the earth. Succeeding ages have confirmed this estimate, so that one of the common marks of opulence and taste in all countries is the selection, preservation, and ornamental use of gems and precious stones. That we may have some precise idea of the substances which I propose to bring under your notice in this lecture, I will state the definition of a mineral as given by Mr. Phillips, viz., "a mineral is an unorganized body, and one which differs from an organized or living body in respect of structure, the manner of formation, and of increase or growth. Organized bodies increase by means of their internal organs, which allow of an internal circulation, approximating and assimilating what is beneficial, and rejecting what is useless; unorganized bodies, on the contrary, increase externally, and possess no internal organization, the particles composing them being attached by mere juxtaposition." In organized bodies, also, you rarely perceive plane surfaces and right angles, such as are presented by the large group of crystals before you: but while such forms in organic nature are extremely rare, in the inorganic or mineral kingdom they are of constant occurrence; every mineral substance, under favourable circumstances, having the property of assuming some definite crystalline form, which it retains as a distinctive character. The crystalline form of minerals, which I have endeavoured to represent by a series of rough paper models, is very important to be known, inasmuch as it preserves the distinction between substances which * Extracted, by permission, from a lecture by Prof. James Tennant, F.G.S., delivered at the Society of Arts, March 24, 1852. 1 to 7, Diamonds; 8 to 11, Corundum; 12 to 14, Spinal-ruby; 15, 16, Garnet; 17, 18, Topaz; 19, Water-worn Pebble; 20, Tourmaline; 21 Quartz; 22, Beryl. Ꮳ 11 PLATE I.-THE MOST COMMON CRYSTALLINE FORMS OF GEMS. From Specimens exhibited by Mr. Tennant, in Class I., No. 14. 10 occasionally resemble each other in many respects. By attending to the forms of the crystals we are quite sure that we shall not find the emerald, sapphire, zircon, or topaz, in the form of a cube, octahedron, tetrahedron, or rhombic dodecahedron; nor the diamond, spinel, or garnet, in that of a six-sided prism, terminated at either end by a six-sided pyramio. For want of a knowledge of the crystalline form of the diamond, a gentleman in California offered 2007. for the small specimen of quartz which I have here. He knew nothing of the substance, except that it was a bright shining mineral, excessively hard, not to be scratched by the file, and which would scratch glass. Presuming that these qualities belonged only to the diamond, he conceived that he was offering a fair price for the gem; but the owner declined the offer. Had he known that the diamond was never found crystallised in this form, namely, that of a six-sided prism, terminated at each end by a six-sided pyramid (see fig. 21, Plate I., which is the exact size and shape of the stone), he would have been able to detect the fact, that what he was offered 2007. for was really not worth more than half-a-crown. Greater experience would have also taught him that diamonds, in their natural state, are devoid of that brilliancy which is given to them by artificial means. The finest crystals of quartz are more brilliant than those of the diamond. From the inferior lustre of the latter in their natural state it is extremely probable that numbers of diamonds are overlooked in the search for gold in Australia, California, and other gold-producing countries. Crystals of diamond are numerous; the three following forms are most common, the faces of which are often curved : a, the regular octahedron; b, the octahedron, having the edges replaced, forming the passage of that solid into the rhombic dodecahedron, fig. c. In Plate I., figures 1 to 7, are also given figures of the exact size of the diamonds exhibited in my case. There is also before you a specimen (fig. 7) which was presented to your notice on a former occasion, about three years ago, when I read before your Society some notes on the probability of discovering diamonds in California. It is a mass consisting of water-worn pebbles of quartz, diamonds, and gold, cemented together by oxide of iron, from a river in the Brazils. The frequency of the occurrence of the several, crystals of diamond may be inferred from an experiment made with an average parcel containing one thousand diamonds. There were one of the form fig. 6, ten of that of fig. 5, fifty similar to fig. 4, and the remainder resembled figs. 1, 2, 3, in about an equal proportion. With regard to the size and weight, five hundred out of the thousand were found smaller than fig. 1, which is the exact size of a diamond weighing half a carat; three hundred were of the sizes 3, 4, 5, 6; none exceeded a carat in weight. Eighty were of the size of fig. 2, each of which weighed a carat and a half. One only was as large as fig. 16: this weighed 24 carats. The remainder varied from 2 to 20 carats, a carat being equal to three grains and one-sixth troy. In the mineralogical department of the British Museum, the case No. 4 affords the best opportunity of studying this gem in all its varieties. This department of our Museum has been greatly enhanced in value within the last two years by the addition of the very fine collection of crystallized diamonds formed by the late H. P. Hope, Esq., and described in Mr. Hertz's catalogue of that collection.* The Great Exhibition afforded special opportunities for the study and comparison of precious stones. From the invaluable contributions of her most gracious Majesty the Queen and those of other sovereigns, down to the collections of the various jewellers of this and foreign countries, the display was such as can never be forgotten by persons of taste sufficient to appreciate its exquisite beauty. Conspicuous above all was the Koh-i-noor, which, owing to imperfect cutting and fractures produced by rough usage, disappointed many a high-raised expectation. Those who were fortunate enough to see it when the sun's rays fell upon it, from two to three o'clock, were gratified with its brilliancy; but at other parts of the day it was so devoid of lustre as to excite the suspicion in many minds that it was no diamond at all-in fact, nothing but a piece of glass. In this case, as in many others, it was necessary to know at what hour of the day the gems could be seen to the best advantage; for example, the diamonds in the Russian department were in their greatest brilliancy at twelve o'clock. The Koh-i-noor was worn by its former owner, Runjeet Sing, as an armlet, and was considered in itself an ornament of such extraordinary value as to allow the wearer to dispense with the decoration of many other jewels. The Hon. W. G. Osborne, describing a visit to the hall of audience of this potentate, says, "The whole space behind the throne was crowded with Runjeet's chiefs, mingled with natives from Candahar, Caubul, and Affghanistan, blazing with gold and jewels, and dressed and armed in every conceivable variety of colour and fashion. Cross-legged in a golden chair sat Runjeet Sing, dressed in simple white, wearing no ornaments but a single string of enormous pearls round the waist, and the celebrated Koh-i-noor, or Mountain of Light, on his arm.' This diamond, in common with many other jewels of great price, was occasionally used to adorn the favourite horses of the potentate. A jewelled bridle, saddle, and other accoutrements, were displayed by the East India Company; and we find from the account given by the Hon. Miss Eden,† that the decorations of such accoutrements were exceedingly valuable. Describing the favourite horses in the Maha Raja's stable, she says, "The jewelled trappings of the horses were of the most costly description, the jewels being chiefly emeralds of immense size and value, hanging round the neck, covering the forehead, and fastened on the front of the saddle. The jewels and ornaments were said to have been worth about 300,000l. The Maha Raja was passionately fond of horses, and he would make war on a province to procure the surrender of any that were reputed of peculiarly pure breed. He kept them, highly fed, in large numbers, and was in the almost daily habit of inspecting them; adorning them on occasions of particular display with the finest jewels of his treasury, including the celebrated large diamond called Koh-i-noor, In the museum at Cambridge is probably the second best collection in England. This collection of diamonds was formed by the late Sir Abraham Hume, Bart., and a catalogue with eighty figures, by M. le Comte de Bournon, was published in 1815. + Portraits of the Princes and People of India,' 1844. |