Such contrasts between mountains and plains occur everywhere. In India the little country of Bhutan on the rugged southern slope of the Himalayas contains only 12 people per square mile, while close at hand the level plain of Bengal has over 500. Even where the con trast between mountains and plains is less striking there are great differences in the density of the population. For instance, in Fig. 32 notice how the people of Scotland are concentrated either in the southern lowland from Glasgow to Edinburgh and Dundee, or else along the plains of the eastern coast where Aberdeen is located. The rugged highlands both in the north and south have so few people that they appear almost white on the map.
The Advantage of Plains over Mountains in Transportation.— We come now to a condition where the relief of the mountains is an especially heavy handicap. In mountainous regions the roads and even the railroads must go up and down hill. Everyone knows how hard it is to haul a heavy load uphill. The load not only has to be carried forward, but must be lifted against the pull of gravity. Another difficulty in a rugged country is that the roads must often wind in broad curves or go out of their way to follow valleys, so that they traverse much greater distances than are necessary on a plain. Com pare the two parts of Fig. 33. The southern part with the straight .railroads belongs to the level plain of southern New Jersey, while the northern part with the curved roads is in the rugged portion of that State.
The hard work and long distances on mountain roads combine to cause three other disadvantages which are not felt in plains. First, transportation is slower. For example, on the level stretch between New York and Philadelphia a fast train on the Pennsylvania Railroad travels 50 miles an hour, while on the mountainous stretch where the road climbs the Allegheny Escarpment over the Horseshoe Curve between Altoona and Johnstown the average speed is only 20 miles per hour. Second, the steeper grades cause greater wear and tear on both animals and engines. In rugged Vermont an automobile is considered " junk " after traveling half as many miles as in level Kansas. Third, the uphill work, the slow speed, and the wear and tear all increase the cost of transportation among the mountains as compared with plains. For instance an automobile that makes 16 miles on a gallon of gasoline in Nevada, can make only 6 when it climbs the Sierras into California. Moreover, the cost of making and especially of repairing roads and railroads is often ten times as much in the mountains as in the level plains.
Looking at the matter from the standpoint of plains we find that they have the following advantages: they permit transportation routes (1) to avoid hard grades, (2) to go in any direction, and to follow straight lines, (3) to form as dense a network as the inhabitants require, (4) to be adapted to rapid travel, and (5) to be built and maintained cheaply.
Why the Means of Transportation Differ in Mountains and Plains.—The most striking difference between the means of trans portation used in mountains and plains is that in the mountains primitive methods are still used while in the plains advanced methods have made much more progress. Even in the most civilized coun tries like Switzerland pack trains are still common among the moun tains, while in the plains of the same countries they are unknown. In plains it is possible to build numerous railroads and also trolley roads not only because the cost of construction is moderate, but because there are many people. Not only are there more plainsmen than mountaineers, but they produce and consume more per capita, and hence provide the railroads with more business. Even the airplane is far more adapted to plains than to mountains, because it requires broad level spaces in which to land.
Since railroads are less numerous in mountain regions than in plains, the mountaineers must rely upon roads and often must carry their products long distances. What is true of railroads, how ever, is also true of roads. In the plains they can be built easily and cheaply and there are many people among whom to divide the cost. In the mountains they are expensive and there are few people to bear the cost. Therefore many parts of the mountains have no good roads, and wagons cannot be used. Hence goods must be transported on pack animals, which can follow rough trails that require no expense for their construction. The animals that have been domesticated for this purpose vary from place to place.
This difference in the means of transportation does even more than the steep grades and the greater distances to make transportation more costly in the mountains than in the plains. For example, it costs about two cents to carry a ton of freight a mile on a level rail road. To carry a ton the same distance on the backs of horses among the mountains often costs from $1 to $5. It may pay to carry cloth long distances by such expensive methods. It rarely pays to carry cheap, heavy articles like iron. If grain were carried from Illinois to New York by this expensive method it would cost at least $20 to $30 a bushel.