Page:Indian Journal of Economics Volume 2.djvu/16

 8 H. STANLEY JEVON$ mined by water transport, in others by the meeting of great road or railway routes. Thus there must always arise a trade between the mouatainous districts and the valley bottoms. Further, as climate changes according to latitude, both the natural vegetable and animal products, and the still more important commo- dities of cultivation must vary so much lengthy north and south trade route that a trade must arise. Again we have desert the arid zones of continents, in the western coast, and a moist climate in the tropics and along the coastal strip; so there is interchange of products between the dy and moist areas. Again the sources of powe are localized and determine the location of industries present and future, at points on exit routes from the coalfields, and in the belt where the mountains abut on the plains and hydro-electric power is cheapest. 2. Potential /o.--In estimating the future economic possibilities of a territory with a view to drawing up a program for development works, it is obviously important to take account of its potential resources. There may be much waste land with a good soil perfectly capabl of profitable cultivation if adequate communications and security of property be established. There may be great stretches of land which would become fertile if irrigated, and for which over any considerable regions in the interior and on shown to be suitable for afforestation, fruit-growing, or for sheep-running. There are very few types of country except precipitous mountains and salt marshes, that cannot be devoted to some useful purpose, if water can be made available , the questions will be-- the kinds and quantiy of produce to be expected, the works aeeded to raise and market it, and the it can be shown that .water can be provided; or a hilly region, now producing little or nothing, may be