Note 14 — Chapter I

"The coal measures of this part of Maryland are usually called the Cumberland coal-field, from Fort Cumberland, famous for the wars of the English with the French and Indians, in which General Washington took part before the American Revolution. The carboniferous strata are arranged geologically in a trough about twenty-five miles long from north to south, and from three to four miles broad. Professor Silliman and his son, who surveyed them, have aptly compared the shape of the successive beds to a great number of canoes placed one within another."—Lyell's Geology, vol. ii., p. 17.