Experiments on two varieties of Iron. 95 



The ore is stated to be in immediate connexion with a primi- 

 tive rock, the chief ingredient of which is, Labrador feldspar. 



Two varieties of ore were received accompanying the two 

 kinds of iron here referred to. 



The first variety of this ore is of a granular, but rather com- 

 pact structure, color of fresh fractures deep black, and shining ; that 

 of weathered surfaces reddish brown, owing to the formation of 

 a Ittle peroxide. Its specific gravity is 4.2322. 



The second variety has a compound structure, being in part 

 amorphous, and in part crystalline. The color is a brownish 

 black, except that of the crystalline portions, which is jet black. 

 Its specific gravity is 4.6636. From this ore, both specimens of 

 the iron were produced, but t^ieir difference consisted chiefly in 

 No. 1 being wrought at a higher temperature than No. 2. 



The locality of these ores, and the site of the iron works, is 

 about forty five miles westward from Lake Champlain, between 

 Lake Sanford and Lake Henderson, which are one mile apart, 

 and according to Mr. Emmons' barometrical measurements, it is 

 at an elevation of one thousand eight hundred and eighty nine 

 feet above tide water. The north branch of the Hudson, in the 

 distance of this one mile, has a fall of about one hundred feet. 



The method of manufacture is by calcining the ore in kilns, 

 breaking up and separating the purer parts by revolving magnets, 

 reducing these parts to a malleable state in a forge fire, and draw- 

 ing the loup out under a common tilt hammer into bars, ready for 

 the market. This, or a similar method, is likewise pursued by 

 the Peru Iron Company, at Clintonville, and at other works in 

 Clinton County, in which about three or four thousand tons of 

 malleable iron are manufactured per annum. 



The appearance of the two varieties of iron, when received, 

 was in some respects different. The structure of No. 1 was the 

 more compact and fibrous, that of No. 2, more granular and crys- 

 talline, as indicated at the ends where the bar had been cut off 

 with the cold chisel. No. 2 also exhibited two or three dark 

 seams running along it longitudinally, and indicating less perfec- 

 tion in the welding than would be desirable. 



Experiments on Specimen No. 1. 



To ascertain the toughness and ductility of this iron when 

 cold, I caused the bar to be bent at a temperature of 50°, at a 



