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



and another still higher, accompanying a bed of ore under the coarse 

 gritstone or conglomerate. This clay, of the 4 feet bed, has a dark gray 

 color, compact structure, and possesses a specific gravity of 2.646. In 

 the fire it becomes reddish M'hite, but is otherwise unchanged except by 

 cracking, as it shrinks, and displaying on the exterior some traces of oxide 

 of iron. 



"Limestone. — Limestone occurs in such quantities as to leave no doubt 

 of its constituting a regular part of the formation. It was observed not 

 only in the bed of Carbon creek, but also in that of the Long valley, Fall 

 creek, and some other tributaries. It is of the gray fossiliferous variety 

 and belongs in the strata below the coal. The fact of having noticed 

 some of it not far from the great falls of Fall creek, has induced me to 

 believe that it must be found in place within a moderate distance of the 

 bottom of those falls. 



" A sample of the limestone picked up in the channel of Long Valley 

 creek, possesses a specific gravity of 2.7054. 



" It contains about 40 per cent, carbonate of lime. 

 " 3.5 " peroxide of iron. 



" 56.5 " insoluble argillaceous matter. 



100.0 

 " This limestone will probably be found sufficiently pure to serve as a 

 flux for any of the ores above enumerated. 



" As the valley of the Towanda creek, below its junction with the Car- 

 bon creek, presents many localities where fossiliferous limestone of lower 

 strata than that above described, are brought into view, it was deemed 

 proper to make also some trials to determine its degree of purity : its 

 color is reddish gray. Its specific gravity is 2.658. 



It yielded of carbonate of lime, - - - 45.5 per cent. 



" peroxide of iron, - - - 5.5 " 



" earthy argillaceous matter and sand, - 49.0 " 



100.0 



Besides the geological character of this county, and an analy- 

 sis of the minerals, Prof. Johnson has given some valuable state- 

 ments respecting the timber, water power, and facilities for trans- 

 portation afforded by a continuously descending line of railroad, 

 of which he has traced the route and given the details of grade, 

 direction, and expense. The amount of surveying and levelling, 

 including that which refers to geological, as well as to topograph- 

 ical purposes, amounts to upwards of thirty-five miles, and when, 

 the direction of this part of the work is added to the actual explora- 

 tion of a wide tract of wilderness, in which scarcely a bridle path 

 is said to have existed before it was cut out by the exploring par- 



