I047

To Paint a Figure which may appear twenty four Fathoms high, on a Wall of half that height, Observe what follows: Let one half of your Figure be Designed on the Wall M N, and the other half on the Arch M R; in order to which, take the ensuing Method: In the first Place, on some convenient Place trace out a Wall with an Arch, of the same Form, and in the same Proportions, with those whereon you are to Paint; This done, place a Model of your Figure, Design'd in Profile, and of what bigness you please, behind this imaginary Wall; drawing Lines from every part of it, to some fix'd Point, as F, and observing in what Places they cut the same supposed Wall, M N; that you may be afterwards enabled to set them off on the real one: By this Means, you will find all the Heights, Juttings out, and the several remarkable Points in your Figure: as to the Breadths and Thicknesses, those which are projected on the straight Wall M N, will be found in their due Dimensions, the Figure being sufficiently diminished, by its distance from the Wall: But, that part of the Figure which enters the Curviture of the Arch, must have its Breadths and Thicknesses further diminished, in the same Manner as if it were straight; and to proceed the more surely, it may be convenient to mark out this Diminution, on some even Plane, where you may lay your Figure, taken off from the seign'd Wall, N R, to be afterwards Transferr'd in its just Proportions to the Real Wall. This is a Method, which I dare venture to recommend as the best, and the most secure, that can be us'd on these Occasions.