A carving in the spandrel of an arch at Worcester cathedral, appears to deserve especial notice, in connection with the subject under consideration. It is figured in Carter's Ancient Architecture, and represents an architect, who, having drawn his design on tablets, is presenting them to an ecclesiastic, probably the superior of the monastery. The figure given by Carter is so small that it is not easy to make out anything from the draft on the tablets, but if any proportion was observed, it seems clear that the tablets must have been of wood, or the abbot could not hold them as he is there represented. It is curious however, that the architect has also what appears to be a roll of old parchment; its breadth is such compared with its length that it seems very probable it is a description of the work to be done, or something in the nature of an estimate. The architect also has in his hand something which appears like a bevel square, but the representation of it is so rude, that one can hardly draw any conclusions from it. This piece of carving is, so far as I know, the only direct evidence we have on the subject; there may however be examples of the same kind in other places, as also in some ancient MSS[1].
There is a citation in the account of Roslyn chapel in Britton's Architectural Antiquities, which may deserve notice, as tending to corroborate the idea that wood was used by ancient architects for the original designs. It is taken from a MS. memoir of the house of Douglas, in the Advocates' library at Edinburgh. It runs as follows, speaking of the founder, William Saintclair, earl of Orkney.
"The fundation of this rare worke he causd to be laid in the year of our Lord 1446. And to the end the worke might be more rare, first he causd the draughts to be drawn upon Eastland boords[2], and made the carpenters to carve them, according to the draughts theron, and then gave them for patterns to the masons, that they might therby cut the like in stone."
Our principal marking materials at the present time are the useful China or Indian ink, and portions of plumbago set in cedar: of the antiquity of these substances I have been unable to ascertain anything at all conclusive. With regard to the means employed for effacing erroneous lines, mention is made of the crumb of bread, by some early Italian writers, but this
