Density

in Physics, is quantity of material in a given bulk, and varies directly with the quantity and inversely with the bulk. In Economics, it is the number of persons per mile or per acre. The D. of large English towns varies from under 20 per acre in Norwich, Leeds, Sheffield, and Nottingham, to over 100 in Liverpool. Birmingham, Bristol, and London have about 49, and Manchester has 85. The D. of European countries varies from about 16 per square mile in Norway, and 27 in Sweden, up to 485 in England, and 520 in Belgium. France has 187, Germany 221, Ru ia 42. The U.S.A. have 18.