DIRECT communication between the Mediterranean coast and Central Africa, via the Sahara, is possible by two routes. The more easterly, exploited by the Societe Algerienne des Transports Tropicaux, starts from Algiers and passes through the Ahaggar mountains, its termini being Kano and Fort-Lamy, with an extension westward to Niamey. The western route, operated by the Compagnie Generale Transsaharienne, starts from Colomb Bechar, which is reached by railway from Oran or Algiers, and, roughly speaking, follows the meridian across the Tanezrouft to the Niger at Gao, whence it continues to Niamey. On both routes hotels and depots have been built at convenient intervals and regular transport services are operated, accommodation being provided for passengers. The S.A.T.T. runs a weekly service as far as Tamanrasset in the heart of the Ahaggar mountains, and a fortnightly service beyond. The Transsaharienne services run once a week. The desert is virtually closed between the end of May and beginning of October and no public services run right across. Because there is a regular transport service on each route, it must not be assumed that there are roads across the desert. There is merely a track which has been cleared of major obstacles and is marked, where possible, in an unmistakable fashion. Driving sand winds however may completely obscure the track between markers and, if these are far apart, it may be necessary to steer a compass course until the track once more becomes recognizable. As the track is not metalled or provided with any artificial surfacing, it quickly deteriorates and it is generally found more convenient to mark out a fresh track when the old one is worn out. Old tracks are generally shown as closed by the simple expedient of laying a row of stones across the entrance to them. On both routes the tracks now in use may be expected to provide the hardest surface available in any particular region, but new and better ways are constantly being discovered and for this reason the mileage by either route may, between certain points, vary considerably in difFerent years. Where the ground is hard gravel the heavy lorries, used for the regular transport services, have rolled the track into a series of corrugations, which provide extremely uncomfortable running for a private car. When large expanses of sand have to be crossed, the track may be a quarter of a mile wide or more, for each driver seeks to avoid the ruts made by others and makes his own way across the virgin sand to the right or left of the route. Where sandy wadis, or dried-up river beds, have to be crossed, the approaches have been eased off by working parties and causeways of stones or reeds provided. On the Ahaggar route the track resembles a road wherever it passes over hard ground or through the mountains, for the larger stones have been moved to each side, clearly defining a highway of constant width. Where the track has been badly marked however there may be two or three parallel tracks made by drivers in search of better surfaces. At night it is unwise to follow any except the main track, however badly surfaced this may be. Across large