MECHANICS AXD USEFUL AETS. 41 



which, found in the treasury of Lahore, India, were confiscated and 

 given to the queen. They are engraved with dates of the Moham- 

 medan era from 1070 to 1168. Other curiosities were an emerald, 

 almost without a flaw, weighing one hundred and fifty-six carats; 

 another emerald, imperfect, weighing three hundred and seventy- 

 seven carats, and claimed to be the largest in the world ; a ruby, 

 weighing one hundred and one carats, and a small profile likeness of 

 the queen, not much larger than a postage-stamp, which was composed 

 of nearly twelve hundred minute but distinct diamonds. Emanuel, the 

 celebrated London jeweller, showed many specimens of an old fashion 

 of setting precious stones in ivory, that is, " ivory-jewelry ; " and a 

 more attractive setting for some kinds of gems, viz., that styled the 

 "pink coral" jewelry. This material, however, has nothing to do 

 with coral, the pink base in which the jewels are set being cut out 

 of a delicately-tinted shell found in the West Indies, which much re- 

 sembles rose-colored mother-of-pearl. With the aid of this shell and 

 the ivory some remarkably beautiful combinations are produced, es- 

 pecially when the jewels are carefully chosen to suit the settings. 



Other novelties in jewelry were the so-called " rock-crystal brooch- 

 es," engraved like intaglios, and painted from the back ; their curios- 

 ity consisting almost entirely in the excellence of the painting, which 

 requires great skill, inasmuch as the first touch of the brush must also 

 necessarily be the last; the " granite jewelry," manufactured in Aber- 

 deen, Scotland, some specimens of which were very fine, the grain of 

 the stone revealing depth and richness of hues; and a cup, taken from 

 the Emperor of China's palace, made of a human skull, inlaid with 

 precious stones and supported upon a massive gold pedestal. 



In the French department a most curious exhibit was made of arti- 

 ficial pearls and gems. One exhibitor showed ten strings of pearls, 

 one, real, valued at twenty thousand dollars, and another, false, worth 

 two hundred dollars, and defied connoisseurs to distinguish, by sight 

 alone, between the two. The false gems, for which the French are 

 so justly celebrated, were exhibited in every stage of manufacture, 

 from the mass of paste composition in the crucible to the cut and set 

 stones. Here, again, the eye is completely at fault, the taste of the 

 manufacturer leading him to discard all extravagances, the more 

 completely to deceive. The price of these fictitious gems was, how- 

 ever, very high. 



Aluminum was shown in a great variety of useful and ornamental 

 forms. We would specify soldiers' helmets and sextants, both won- 

 derfully light ; also door-keys of aluminum alloyed with a small per- 

 centage of nickel. A fine display was made of fancy articles com- 

 posed of ten parts alloyed with five of copper, the whole an alloy of 

 great hardness, of the exact color of gold, and almost as free from 

 liability to tarnish as the precious metal itself. At present the price 

 of aluminum has fallen to about seventy cents per ounce, and for 

 jeweller's work one ounce of aluminum will go as far as five or six of 

 silver. M. Garepou, of Paris, now furnishes aluminum wire at from 

 sixty to one hundred per cent, cheaper than silver wire of the same 

 size. He exhibited in the Exhibition articles of lace-work, epaulets, 

 textile fabrics, head-dresses, etc., with mountings and ornaments con- 

 structed entirely of aluminum. 



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