Contenu du sommaire

The history of the isthmus of Panama, from Christopher Colombus to our day, can be seen as the piling up of various networks, either competing or complementary, on this narrow albeit strategic strip of land. These infrastructures symbolise the relation of America to itself and to the other continents, and underlie the history of the state of Panama. As the canal is becoming techologically obsolete, the geopolitical fate of the state of Panama in a context of globalisation is unclear.

The Canal de Castilla is the most ambitious and best conceived project in the Castilla history, one the most important hydraulic projects of Spanish Enlightenment. Its construction was slow, it was delayed by the Independence War and the consequent economic disaster, interrupted several times because of doubts or lack of money. Today the Canal is a hydraulic infrastructure working efficiently for the irrigation of the adjacent lands and for local water supply, and the Confederacion Hidrografrica del Duero is the authority which manages correctly its essential waters for the villages, towns and countrysides. In 1985 the Canal was stated historical monument. The existing architectural and technological heritage is immersed in a very rich complex of natural and lanscape values. These building elements, with the hydraulic and natural systems, must be protected. The Canal shows how an artifact, a creation of man, can be integrated in the landscape and become one of its essential components.

The Paris-Lyons axis is very important among French traffics. Transport equipments have been dense, varied and numerous for a long time. The use of six means of transport makes it possible to observe a wide range of relations between networks. The main driving force remains competition, for freight as well as passengers, including all its different aspects through time. But cooperation is often necessary, ranging from a relative equality between the various parties (spatial continuity) to tenser relationships between dominant and dominated elements (functional complementarity), or even exacerbated ones (drainage and diffusion transport). The flows hierarchy has changed through time according to endogeneous factors (distance, roughness, intricate pattern of local influences), but also exogeneous ones (state policy, integration within national networks, wide spatial structuration).

Gas networks were, in their beginnings, an affair with a high degree of economic risk. On the one hand, they required an important volume of initial capital; on the other hand, the demand for gas was unknown. To manage this risk, a very accurate entrepreneurial behavior was necessary to assure the control over the territory and the continued expansion of the network. In the beginning of gas networks' spread, the mercantilist mechanism of exclusive privilege would give to the entrepreneurs a certain safety margin, because it granted them a monopoly in an urban territory for a number of years. This practice, customary in continental Europe, was transformed afterwards into a grants regime, which, in essence, produced the same effect as the privilege. In Spain, the absence of a specific legal framework for the gas industry permitted a situation of uncertainty, which caused numerous conflicts. Only until 1924 would the gas industry be considered in Spain as a public service. This paper examines the case of the growth of gas networks in Barcelona and analyzes its different stages. After a monopoly phase, the gas industry evolved into one of networks multiplicity and competition between companies. This situation was solved first, by the sharing out of the territory and later, by the unification of networks, and, therefore, by a new situation of monopoly.