306 ANTHRACITE COAL-FIELDS. 
be traced parallel to the Kittatinny, nearly the whole 
way from the Susquehanna to the Lehigh, more than 
60 miles. Near the middle of this line, which is 
chiefly along a valley embraced by the Sharp and 
Broad Mountains, about 65 seams have been count- 
ed, one half of which, at least, are productive, and 
those wrought will average five feet in thickness ; 
while many are much thicker, some having a thick- 
ness of 24 feet. These seams, cropping to the sur- 
face under a mean dip of about 30 degrees, thus 
present a front of 200 or 300 feet of coal above the 
level of the valleys, from which they are entered 
by drifts or levels carried in from the ends of these 
ridges. Near the northeast end of this coal-field 
the seams are greatly reduced in number ; but one 
of them, that known as the Summit Mine of the Le- 
high Company, measures in thickness nearly 60 feet 
of solid coal. 
We have not space to enter upon a description 
of all the coal-fields of this magnificent state. We 
may, however, briefly notice that which lies north- 
west of the Broad Mountain. Here are immense 
beds of coal, lying nearly horizontal, and with a 
thickness throughout of between 20 and 30 feet. 
The extreme northeastern coal-field of this region, 
or that lying along the valley of the north branch 
of the Susquehanna River, from 10 miles below 
Wilkesbarre to Carbondale on the Lackawanna, 
occurs under sufficiently simple features to enable 
lis to estimate, with some degree of precision, the 
probable amount of the coal in it. This field is 
about 40 miles in length, with an average width of 
more than two miles, and the coal ranges in at least 
six seams continuously throughout the whole of 
this valley. Computing the solid matter accessible 
in only the two thickest of these, one of which is 24 
feet, and the other six feet thick, and making due 
allowance for loss and waste in mining, we find that 
the coal-fiield in question can be made to furnish at 
