The ancients had little suspicion of all this. Yet the contrast between the land world and the water world did not escape Strabo’s keen glances, and he hints at its effects on man. It is glanced at in one passage of his 15th Book. He is speaking of the effect of the moist air of India in contrast with the dry air of Libya, and shows that he appreciates that these are not without their influence on the constitution of the Indian and of the Ethiopian. “Some,” he says, “rightly ascribe it to the sun, that, in the absence of moisture in their air, the rays burn so deeply into the body of the African; the Indian, on the other hand, is not jet black and curly-haired, because, in his country, he enjoys the moisture in the atmosphere.” The Position of the Continents and its Influence on the Course of History. Besides the three great forms spoken of above—the compacted land-mass, the great water-mass, and the subordinate water-mass—the position of the continents leads us to another discovery of prime importance. The question arises, What relation have the continents, taken separately, to the entire mass which they constitute? What relation do they bear to each other? What influence does the proximity of great land forms exercise? What influence their remoteness from each other? Is the arrangement of the continents fortuitous, or adapted to great ends always held in view by the Creator? Has Nature been left in this to a wild, passionate caprice, or has she been subjected to law, and been compelled to subserve the interests of humanity? And is it not worthy of study, worthy of science, to investigate these things, to master their law, and observe here the workings of the Divine Mind? In the solar system, we have for a long time minutely studied matters of size and distance, the approach and receding of planets, and observed the effects of all these things with an accuracy which could not be too thorough. In the study of our Earth, this has been neglected, because heretofore those great tracts of land and water have seemed of little mutual influence; because they are fixed forms. Yet they have a greater influence, perhaps, on this very account. Although there is in them no law of gravitation to study, yet there is in them the display of forces no less surprising than those of attraction, and which are to be read in the light, not of mathematics, but in the light of history. It indeed seems self-evident that a grouping of these great forms cannot be without an influence on the progression or retarded development of nations; on the amount of population, the progress of colonization, and the union of States in offensive and defensive alliance. Should a higher Power throw the continents out of their present position and relation to each other, a new history of the world would date from this day.