October !), 1903.] 



SCIENCE. 



461 



of tint within them as the number of people 

 per square mile increases, until absolute 

 blackness represents, say, over 2,000 people 

 per S(iuare mile. Such maps are the best 

 means of displaying: the geography of the 

 available sources of energy in a country at 

 any particular period. Population maps 

 of England and AVales in the early part of 

 the eighteenth century would be pale in 

 tint with a few rather darker patches, and 

 would show a di.stribution dependent solely 

 upon food as a source of energy working 

 through the medium of mankind and 

 animals. Such maps would be purely agri- 

 cultural and maricultural, dependent upon 

 the harvests of the land and sea. Maps 

 made at a later period would show a new 

 concentration around other sources of 

 energy, particularly wind and water, but 

 would not be perceptibly darker in tint as 

 a whole; for although we are apt to think 

 that we have in this country too much wind 

 and water, they are not in such a form that 

 we can extract any appreciable supply of 

 energy directly from them. 



But maps representing the present popu- 

 lation, while still mainly energy maps, at 

 once bring out the fact that our leading 

 source of energy is now coal and no longer 

 food, wind or water. The new concentra- 

 tions, marked now by patches and bands 

 of deepest black, have shifted away from 

 the agricultural regions and settled upon 

 and around the coal fields. The map has 

 now become geological. 



The dift'erence between the old and the 

 new map is, however, not only in kind ; 

 it is even more remarkable in degree. The 

 population is everywhere much denser. 

 Not only are the mining and manufactur- 

 ing areas on the new map more than eight 

 times as densely populated as any areas on 

 the older map, not only is the average 

 population five times greater throughout 

 the country, but the lightest spot in the 



new map is nearly as dark as the darkest 

 spot on the old one. The sparsest popula- 

 tion at the present day is as thick on the 

 ground as it was in the densest spots indi- 

 cated on the older map, while at the same 

 time the standards of wages, living and 

 comfort, instead of decreasing, have in- 

 creased. 



The discovery of this new source of 

 energy, coal, immediately gave employment 

 to a much larger number of people; it 

 paid for their food and provided the 

 means of transporting it from the utter- 

 most pai-ts of the earth. Under agricultural 

 conditions the map shows that the popula- 

 tion attained a given maximum density, 

 and no further increase was possible, the 

 density being regulated by the food supply 

 raised on the surface of the land. Our 

 dwelling-house was but one story high. 

 Under industrial conditions our mineral 

 resources can support five times the num- 

 ber. Our dwelling-house is of five stories 

 — one above ground and four below it. 



At the same time the type of distribution 

 is altered. .The agricultural areas are now 

 covered by a relatively scanty population, 

 and the dense areas are situated on or near 

 to the coal and iron fields, the regions 

 yielding other metals, those suitable for 

 industries which consume large supplies of 

 fuel, and a host of new distributing centers, 

 nodal points on the new line of traffic, 

 either inside the country or on its margins 

 where the great routes of ocean transport 

 converge, or where the sea penetrates far 

 in towards the industrial regions. 



It has been the good fortune of this 

 country to be the fii"st to realize, and with 

 characteristic energy to take advantage of, 

 the new possibilities for development 

 opened up by the discovery and utilization 

 of its mineral wealth. We were exceed- 

 ingly fortunate in having so much of this 

 wealth at hand, casv to get and work from 



