SUMMARY.
We would summarize our findings as follows:
The report is accompanied by plates winch present a full set of plans of the city of Scranton and the mine workings thereunder, and also cross sections showing the positions of the several beds of coal and the intervening strata. From these plates one can readily determine, at almost any given point, the depth of the coal below the surface, the thickness of the beds, and the thickness of the intervening strata, since all of the plans are drawn to scale. These plates should be carefully studied in connection with the report and tables. As provided for in our contract, these plans are based upon information obtained from the maps, records, and data loaned to us by the several mining corporations, the Pennsylvania geological survey of 1885, and from our own personal investigations and measurements.
It will be noted that the coal basin underlying the city is wide and comparatively shallow, so that the coal beds and the intervening strata are comparatively flat, by reason of which fact the artificial pillars that may be inserted are not at all liable to slip or move on account of the dip of the seams. The only part of the coal measures underlying this city where there is an excessive dip is along the West Mountain, where pitches as steep as 50° are found. There is only a small part of the surface underlain by such pitching seams that carries important improvements, namely, in the vicinity of No. 23 School and what is locally known as the “Notch.”
After about 40 days of careful inspection of underground conditions at all of the collieries operating within the city limits, we find that the total quantity of coal and refuse that has been extracted under the city of Scranton is about 221,000,000 tons.
There has been produced for market from the 27 collieries, 177,000,-000 tons of coal.
The space excavated under the city is about 198,000,000 cubic yards. The total estimated excavation by the United States for the Panama Canal is 195,323,000 cubic yards.
It must not be understood that the hole from which the above material has been taken is still open. It is, of course, impossible to say what percentage of the space excavated remains open, but we would express the belief that it does not exceed one-half of the original, due to the numerous squeezes and cave-ins that have occurred.
After spending more than 40 days’ time studying maps, after testing various materials used and considered for roof support in the
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