Rome, Ancient and Modern

I observed, in a shop in Rome, in 1847, a large plan of that city, in which, on the same surface, both ancient and modern Rome were represented; the shading of the streets and buildings being such as to distinguish the one from the other. Thus, in looking at the modern Forum, you saw, as it were *underneath* it, the ancient Forum; and so in the other parts of the city. Can any of your readers inform me as to the name of the designer, and where, if at all, in England, a copy of this plan may be obtained? If I remember rightly, the border to the plan was composed of the Pianta Capitolina, or fra…