458 



METALS. 



lish is, in great part, made from blende, and is 

 consequently among the most impure, contain- 

 ing more lead than any except the Silesian, and 

 more arsenic than any, except perhaps the 

 New Jersey. The Pennsylvanian is made from 

 silicate of zinc, and appears to be the purest 

 produced, in most cases containing absolutely 

 no impurity, except a trace of cadmium. The 

 impurities in some of this zinc appear to arise 

 from the fact that the crust from the furnaces 

 for making the white oxide, in which less care- 

 fully selected ores are used, has occasionally 

 been worked into spelter. The New Jersey is 

 made from the red oxide of zinc, and has hith- 

 erto been supposed to be especially pure, but 

 proved to be just the reverse, containing very 

 appreciable quantities of copper and arsenic, as 

 well as sulphur, carbon, and tin, but less lead 

 than any except the Pennsylvanian. The au- 

 thors were unable to detect the source of the 

 copper, and seem to suspect that, though in 

 considerable quantity, it may prove to be acci- 

 dental; but arsenic was found in both the red 

 oxide and the associated Franklinite, as well as 

 in white oxide manufactured from them. 



Iron and Anthracite of Pennsylvania. The 

 " Annales des Mines " for June, 1861, contains 

 a report from M. de la Fosse, French consul in 

 Philadelphia, on the progress of the manufac- 

 ture of iron with anthracite in Pennsylvania. 

 He states that 1,800,000 tons of iron ore are 

 annually smelted with it, much of which, owing 

 to foreign competition, could not have been 

 used if only bituminous coal or charcoal had 

 been obtainable; that in Pennsylvania 91, and 

 iti New York, New Jersey, and Maryland 

 21) blast furnaces are worked with anthracite, 

 producing 500,000 tons of cast-iron, worth in 

 Philadelphia and New York at least $10,000,- 

 000. lie institutes a comparison between the 

 antbracite iron, costing $20 a ton, the char- 

 coal iron of Eastern Pennsylvania, worth $26, 

 the iron made with coke in "Western Pennsyl- 

 vania, which he considers, from the cost of 

 transport and inferiority of quality, can seldom 

 compete with either of the others, as well as 

 with the English iron, then costing $22, includ- 

 ing duty, but which he thinks would soon reach 

 $26, if England, in addition to her present sup- 

 ply, had to furnish the 500,000 tons now made 

 with anthracite. He considers this to be the 

 best iron made with mineral fuel, being appli- 

 cable to most purposes for which charcoal iron 

 was formerly used, and ascribes this superiority 

 to the small quantity of sulphur in the coal, and 

 the more complete volatilization of foreign in- 

 gredients by the intense heat obtained by a 

 pressure of air nearly three times as great as in 

 coke furnaces. From 1845 to 1855 most of the 

 furnaces had blowing machines capable of 

 throwing in 4,000 cubic feet of air per minute 

 at a pressure of 4 Ibs. to the square inch, which 

 gave with furnaces 40 to 50 feet higli about 

 5,000 tons annually. Since that time more pow- 

 erful ones have been introduced, giving 10,000 

 cub. ft. per minute, at a pressure of 8 or 9 Ibs. 



to the square inch, and with these, a furnace 60 

 feet high will yield 10,000 tons per annum. 

 The combustible necessary for this production 

 is 12,000 to 15,000 tons, while formerly 25,000 

 to 30,000 tons of charcoal would have been re- 

 quired. The cost of labor has also been con- 

 siderably reduced. He states that the arrange- 

 ments for burning the gases, heating the boilers 

 and the blast, are the same as those used in 

 France, and that the air is generally intro- 

 duced at a temperature of 600 F. 



Production of Pig-iron in Scotland. The 

 number of blast furnaces in operation in Scot- 

 land in 1861 is stated to have been 123, and the 

 product of pig-iron as 1,050,000 tons. The 

 shipments to the United States were 54,482 

 tons, those of 1860, 77,032 tons. Scotch pig- 

 iron is largely employed in iron foundries . 

 throughout the country, and is highly es- 

 teemed, not so much on account of its superior 

 quality when used alone, as for the excellent 

 product of its mixture with our own much 

 stronger pig-irons. No other irons can be ob- 

 tained in such large quantities, of so uniform a 

 character, and so well adapted for foundry pur- 

 poses. A large portion of the product is con- 

 sumed in Scotland, much of it in the construc- 

 tion of iron steam-ships and steam machinery. 

 This business is carried on to a great extent on 

 the river Clyde, where, in 1861, 86 iron steam- 

 ers were built. Nearly 100,000 tons of pig- 

 iron are exported to Germany, and about 60,000 

 tons to France. 



Heat of melted Cast-Iron and some other Metals 

 and Alloys. The "Annales des Mines" also con- 

 tains an account of a series of experiments un- 

 dertaken by MM. Minary and Resal on the 

 degree of heat required to fuse cast-iron, the 

 metal employed being a gray iron made with 

 coke at the furnace of Rans, and composed of 

 iron 0'9450, silicium, 0'0195, carbon, - 0309, 

 loss, &c., 0'0046. The calorimeter employed 

 was a vessel of sheet iron containing a weighed 

 quantity of water. The melted iron was 

 poured into a pan supported on legs under the 

 surface of the water, and the temperature of 

 the calorimeter at the beginning and end, the 

 temperature of the air, and the weight of the 

 water and iron, being known, the quantity of 

 heat corresponding to one kilogramme of iron 

 can be calculated. "When the iron was at its 

 lowest temperature of perfect fusion, a very 

 slight crust beginning to appear on the surface, 

 the heat developed was from 250'07 to 257'72 

 units of heat. Very hot iron gave 292'04 units. 

 Iron nearly solid gave 224'93. Iron cooled 

 sufficiently to become somewhat granular and 

 coherent, 215'2. These results are but little 

 less than those which should theoretically be 

 produced by the quantity of fuel used. Simi- 

 lar experiments with other metals gave for a 

 white cast-iron, also from Rans, at the lowest 

 temperature of perfect fusion, 246 to 248 units, 

 though this result seems to be subject to doubt; 

 for copper, very hot 182*0, only just fluid 139 ; 

 for tin, at a red heat 47'5, just fluid 26'0 ; for 



