La fortificazione dell'isola di Carloforte. Logiche militari e disegno illuminista nell'opera dell'ingegnere piemontese Augusto De la Vallea

In the first half of the eighteenth century the island of Carloforte is the subject of a project aimed at the birth of a new settlement. The intervention has a strong affinity with the eighteenth-century Spanish settlements (Nueva Tabarca, 1775) both from an urban point of view and for the common events related to the redemption of the inhabitants of the island of Tabarca in Tunisia. The new fortified city thought by the Piedmontese engineer Augusto De la Vallea - operating in Sardinia in the period 1735-44 - occupies a strategic position close to a hill that, facing the south-western coast of Sardinia and protected from the prevailing winds, check the docks on the island and the nearby salt pans. The project of the military technician previews the realization of a fortified citadel modelled from the shape and from the disposition of plastically defined bulwarks to adapt to the topography of the places and to guarantee the control of the surrounding territory. The drawing, drawn up with considerable skill, describes the landscape context, the methods of tracing the perimeter of defence and through a design practice "Enlightenment", orders the urban layout, planning the layout of the urban space according to a Cartesian layout modelled, in its outer perimeter, by the silhouette of the fortress. A new line of defence, wider and embracing the citadel and showing a settlement developed towards the coastline, is readable in documents of the early nineteenth century that dated 1808-1810, represent a part of the perimeter of the citadel designed by De la Vallea. The contribution proposes a careful graphic-design analysis of the project of the Piedmontese engineer, an analysis of the construction events and a comparison with the most recent documents and the current urban layout of the city.