There is so great a contrast in trade, population, and production between northern Algeria and the Sahara in the south that the same measures of transportation can hardly be applied to both. A traffic flow of only one vehicle per day over a road in northern Algeria would indicate an insignificant rural route, but in the southern Sahara it would indicate a surprisingly well-traveled "main highway." A single rail line near Algiers may carry more tonnage in a day than several years of camel transport over a web of trails in the famous sand dune regions of the Sahara. Since the purpose here is to consider the major trade routes in accordance with their importance in the geography of each area, the scale of the study will be adapted to each region in turn. After the introductory section, attention will be focused first on northern Algeria, and then on the Sahara, where it will be necessary to magnify the faint trails and feeble traffic to show the position they play in the changing economy of the desert. For both regions, a brief outline of the early periods will be followed by a detailed account of recent changes in trade routes.
PHYSICAL FEATURES AND TRADE ROUTES
Transportation has been a major concern of Algeria throughout many periods of history. Like the other Barbary States, Algeria consists of three natural regions: a Mediterranean strip along the coast which has dry summers and mild winters with sufficient rainfall for agriculture, a parallel region of semiarid or steppe country, and then the immense Sahara. Trade between contrasting coastal and interior lands was a traditional part of economic life, even before the development of mineral and agricultural exports with a return flow of manufactured goods.
At the same time, the fringe of Mediterranean and steppe country forms an east-west corridor between the desert and the sea, providing a link among the Barbary States and continuing to the Near East. (Map 1.) This coastal zone, aided by seaports and sea routes, has often dominated the trade of the interior, and formed the heart of nations which extended to undefined limits in the Sahara. The Mediterranean fringe was used for conquest or administration by a succession of peoples--the Phoenicians, Romans, Vandals, Arabs, Turks, and French.
A complicating factor in the basic pattern of north-south and east-west routes is provided by landforms. The productive part of Algeria is mostly hill or mountain country. Coastal plains do exist, but they are small and are separated into isolated basins by the intervening mountains. When viewed as a whole, the portion of Algeria which has Mediterranean climate consists of the Tell Atlas, a mountainous zone with an east-west trend. To the south of the Tell Atlas lie the High Plateaus of Algeria, corresponding roughly to the zone of steppe climate. A second and lower east-west mountainous zone, the Saharan Atlas, separates the High Plateaus from the Sahara with its more arid climate. Thus the coastal region, which has a favorable climate and easy communication with the sea, has the disadvantages of mountainous terrain and isolated valleys; straight and level land routes are rare.
From the above conditions, one would expect a basic transport pattern (trails . . .