FIG. 8.-Vertical Sections of the Coal-Measures of the Wyoming or Northern Coal-field, in Luzerne and Lackawanna counties, Pa. [published by permission of the Second Geological Survey of Pennsylvania, Charles A. Ashburner, asst. is charge of the anthracite coal-fields].

P. 8-Philadelphia and Reading Coal and Iron Company FIG. 10.-Cross-Section in the Southern Anthracite Coal-field

Pottsville Shaft (1882).

Pennsylvania [P. W. Sheafer, 1880].

FIG. 11.-Rate of Increase of the Demand for Anthracite Coal in the United States.

Mr. Joseph 8. Harris in the above diagram (Fig. 11) the probable rate until 1930. Table IL shows the shows the rate of increase in demand since 1830, and present number of collieries in the anthracite region.