MINING CONDITIONS UNDER CITY OF SCRANTON, PA.
Delaware, Lackawanna (Sc Western Coal Co. collieries—Continued.	Co
to
CAYUGA COLLIERY AND STORRS COLLIERY.
(Work section between Keyser Valley and Leggetts Creek, from Bloom Avenue to foot of West Mountain.)
General conditions.
Eroded.
268 acres mined. Depth, see sections on Plates 11 and 13; thickness, 4 feet 8 inches, includes 8 inches of refuse; pillars now being removed; space stowed with gob and surplus rock from a lower bed.
168 acres mined. Depth, see sections on Plates 11 and 13; thickness, 4 feet, includes 8 inches of refuse; falling roof, 2¿ feet thick, closes the mine after standing; now mining top split of Four-foot, 20 inches thick, and stowing surplus rock in 5-foot vein.
490 acres mined. Depth, see sections on Plates 11 and 13; thickness, 8 feet, includes 8 inches refuse; caved in many places; bad fire-clay roof which falls soon after working stops; pillars strong.0
174 acres mined. Depth, see sections on Plates 11 and 13; thickness, 3 feet 3 inches clear; taking down 2\ feet of roof for height; roof good; conditions fair.
623 acres mined. Depth, see sections on Plates 11 and 13; thickness, 10 feet, 1 foot 3 inches refuse; old mine caved and closed.
Not mined; too thin.
576 acres mined. Depth, see sections on Plates 11 and 13; thickness, 8 feet, includes 2 inches refuse; many local falls, but no general squeeze; workings now being flushed with culm.
Not mined, but now being opened.
Not mined; opening in preparation.
Do.
Coal beds.	Name of school.	Mining conditions under school properties.
Eight-foot			
Five-foot		No. 22		
		Depth, about 124 feet; mined, but inaccessible on account of danger due to falling roof.
		
Diamond			Depth, 186 feet: approached to 60 feet from school; pillars sound and of fair size; openings closed by falling roof; roof will not stand after timbers rot; pillars do not crush.
		
		Depth, 280 feet; pillars sound; rooms gobbed on one side; conditions good.
		
Big			
New County			
Clark			Depth, 476 feet. This section of working flushed to within 2\ feet of roof; flushing still in progress.
	No. 23		
Dunmore No. 1			
Dunmore No. 2			
Dunmore No. 3				do	
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a Surface subsidence may and often does occur where pillars are strong, and without much warning or crushing of pillars, if conditions exist as those under Hyde Park, where many thick beds lie close together and the pillars in the several beds are not columnized; the pillars of an upper bed are thus permitted to break through the strata which separate the seams into the chambers or openings of an underlying bed.