192 Scientific Intelligence — Arts, 



iiig his work ; but the kinds now employed, and which experience 

 has taught him are best for his purpose, are the Bull's Mouth, the 

 Black Helmet, the Horned Helmet, and the Queen Conch. The 

 two first are the best shells. After detaihng the peculiarities of 

 these shells, the writer proceeded to give an account of the progress 

 of the art, which was confined to Rome for upwards of forty years, 

 and to Italy until the last twenty years, at which period an Italian 

 commenced the making of them \\\ Paris ; and now about 300 per- 

 sons are employed in this branch of trade in that city. The number 

 of shells used annually, thirty years ago, was about 300, the whole 

 of which were sent from England ; the value of each shell in Homo 

 being thirty shillings. To shew the increase of this trade, the num- 

 ber of shells used in France last year was nearly as follows : 



Bull's Mouth 80,000, average price Is. 8d., value L.6400 



Black Helmet 8,000, ... 5s. Od., ... 1800 



Horned Helmet 500, ... 2s. 6d., ... 60 



Queen Conch 12,000, ... Is. 2M., ... 700 



100,500 shells. Sterling L.8960 



The average value of the large cameos made in Paris is about 6 

 francs each, giving a sterling value of L. 32,000 ; and the value of 

 the small cameos is about L.8000, giving a total value of the cameos 

 produced in Paris for the last year of L.40,000 ; while in England 

 not more than six persons are employed in this trade. — Athcnceum, 

 No. 1018, p. 470. 



14. Smelting by Electricity. — The lately patented process of 

 smelting copper by means of electricity, says a London journal, is 

 likely to effect a change that will be quite prodigious. It produces, 

 in less than two days, what the old process required three weeks to 

 effect. And the saving of fuel is so vast, that in Swansea alone, the 

 smelters estimate their annual saving in coals at no less than five 

 hundred thousand pounds. Hence, it is clear, that the price of cop- 

 per must be so enormously reduced, as to bring it into use for a va- 

 riety of purposes from which its cost at present excludes it. The 

 facility and cheapness of the process, too, will enable the ore to be 

 largely smelted on the spot. The Cornish mine proprietors are 

 anxiously expecting the moment when they can bring the ore which 

 lay in the mine yesterday into a state to be sent to market to-mor- 

 row, and this at the very mouth of the mine. In Australia, also, 

 the operation of this discovery will be of the utmost importance. 

 Ten thousand tons of copper-ore were sent from Australia to Eng- 

 land last year, to be smelted at Swansea ; and the result was only 

 1600 tons of copper. But Australia in future will smelt her own 

 copper, by a 36 hours' process : saving all this useless freight of the 

 8400 tons of refuse, and saving also the cost of the old and expen- 

 sive process. In a very feyv years, Australia will send to market 



