Prof. Johnson's Report on the Bradford Coal Field. 145 



It lost of water, by heating to 320°, - - 3.8 per cent. 



And at a white heat, - - - - 14.1 " 



Of pig iron, it gave - - - - 48.4 " 



Earthy matter, - - - - - 3.9 " 



"The pig metal was gray, tough, and moderately soft; the cinder 

 opaque, grayish white. In this assay, the cinder was rather imperfectly 

 reduced, and some portions were probably lost. 



" No. 6. This specimen of ore was taken from a pic sunk about 8 feet 

 deep, near Mason's coal mines, on the head waters of Wagner's run : the 

 band of flattened balls, very closely compacted together, is six inches. 

 This band of ore is found near the northeasterly outcrop of the series of 

 coal measures, a kw feet only above the level of the heavy stratum of 

 conglomerate rock, which marks so distinctly the limit of the basin in 

 that direction. In this same locality, are exposed three other strata of 

 ore, the first of which is 5| feet above the one now under consideration, 

 the second 6| feet, and the third about 1\ feet. This last is a band of 

 balls, as will be more particularly stated below ; hence, it will be seen, 

 that all four of these bands of ore may be worked together, within a ver- 

 tical height of 8 feet. The total thickness of the four bands being about 

 18 or 19 inches, and the intervening matter to be mined out, ferruginous 

 slate, and rather friable sandstone, will not, I apprehend, present any se- 

 rious difficulties in the mining. 



" The following section shows the whole of these measures, commen- 

 cing at the top. 



1. Balls of iron ore, - - - - 



2. Slaty sandstone, - - - - 



3. Upper hand of iron ore, - - - 



4. Siliceous iron shale, - - _ 



5. Middle band of kidney ore, 



6. Ferruginous slate, - - - - 



7. Lower band of compact halls of iron ore, - 



8. Iron shale, 



9. Black slate, - - - 

 10. Iron shale, - - - 



" The four varieties of ore found at the above locality, are also met 

 with in various other situations, especially on Long Valley creek, in the 

 bed of which, samples exactly similar to the lower band of the above 

 section, have been observed in numerous places. This band is of a du- 

 rable texture, and appears to resist more firmly than the accompanying 

 materials, the decomposing action of the atmosphere, and hence it con- 

 tinues unaltered in places where all the others have been washed away. 

 The specific gravity of this lower band is 3.265. 



Vol. XXXIX, No. 1.— April-June, 1840. 19 



