Public highways have been constructed between the large cities and to some points on the frontiers, and subsidized stage coaches are run on some of them. The roads are rough and at times almost impassable, however, and the river crossings difficult and dangerous. The large cities are connected with one another by telegraph lines and are in communication with the outside world through Argentina, Chile and Peru. Telegraph service dates from 1880, and in 1904 there were 3115 m. in operation, of which 1936 belonged to the state and 1179 to private corporations. The latter includes the lines belonging to the Antofagasta and Oruro railway, which are partly within Chilean territory. Bolivia is a member of the International Postal Union, and has parcel and money order conventions with some foreign countries. Special agreements have been made, also, with Argentina, Chile and Peru for the transmission of the Bolivian foreign mails. The loss of her maritime department has left Bolivia with no other ports than those of Lake Titicaca (especially Guaqui, or Huaqui, which trades with the Peruvian port of Puno), and those of the Madeira and Paraguay rivers and their affluents. As none of these can be reached without transhipment in foreign territory, the cost of transport is increased, and her neighbours are enabled to exclude Bolivia from direct commercial intercourse with other nations. An exception formerly existed at Puerto Acre, on the Acre river, to which ocean-going steamers could ascend from Para, but Brazil first closed the Purus and Acre rivers to foreign vessels seeking this port, and then under a treaty of 1903 acquired possession of the port and adjacent territory. Since then Bolivia's outlet to the Amazon is restricted to the Madeira river, the navigation of which is interrupted by a series of falls before Bolivian territory is reached. The Bolivian port of entry for this trade, Villa Bella, is situated above the falls of the Madeira at the confluence of the Beni and Mamore, and is reached from the lower river by a long and costly portage. It is also shut off from the navigable rivers above by the falls of the Beni and Mamore. The railway to be built by Brazil will remedy this unfavourable situation, will afford a better outlet for north-eastern Bolivia, and should promote a more rapid development of that region, which is covered with an admirable system of navigable rivers above the falls of the Beni and Mamore. Connected with the upper Paraguay are Puerto Pacheco on Bahia Negra, Puerto Suarez (about 1600 m. from Buenos Aires by river), on Lake Caceres, through which passes the bulk of Bolivian trade in that direction, and Puerto Quijarro, on Lake Gaiba, a projected port said to be more accessible than any other in this region. Whenever the trade of southern Bolivia becomes important enough to warrant the expense of opening a navigable channel in the Pilcomayo, direct river communication with Buenos Aires and Montevideo will be possible.