The photograph of a panel of lettering from the upper part of the Arch of Constantine, Rome, shown in [6], well indicates the effect of shadows in defining the classic Roman letters; and the effect of shadows on an incised letter may be clearly observed by comparing [4] and [5], the former showing a drawing for an inscription in which the Serlio-Ross
alphabet was used as a basis for the letter forms, and the latter being a photograph of the same inscription, as cut in granite. It will be noted how much narrower the thin lines appear when defined only by shadow than in the drawing. The model used for the lettering on the frieze of the Boston Public Library, [7], which shows some interesting modern forms intended for cutting in granite, should be studied for the effect of the cast shadows; while [14], a redrawing of inscriptions on the Harvard Architectural Building, Cambridge, Mass., exhibits an excellent type of letter with widened thin lines for v-cutting in sandstone.
The special requirements of the stone-cut forms for either incised or raised inscriptions are, however, quite apart from the subject of this book, and are too various to be taken up in greater detail here. It is important, nevertheless, that the designer should be reminded always to make allowance for the material in which a letter was originally executed. Otherwise, if exactly copied in other materials, he may find the result annoyingly unsatisfactory.