The realization of the map of the entire Kingdom, at scale 1:100,000, to be carried out by systematic surveys, was decreed by Law of June 29, 1875. The trigonometric and topographic works already undertaken for the map of the southern provinces, were continued and extended to the entire National territory. The 1:50,000 surveys which had been used for the realization of the map of the southern provinces were transformed into the new cartographic system; however topographic works were no longer carried out entirely at the same scale, but at 1:50,000 scale for less important regions, and at 1:25,000 scale for regions richer in topographic details.