Note 111 — GLASS

Señor Lázaro, who has recently made at Madrid windows for León cathedral imitating those of the fourteenth and fifteenth centuries, remarks that with the sixteenth century the process grew more complicated, patterns composed with pieces of a single colour being replaced by glass containing a variety of tints. He has also discovered the following usage of the older Spanish craftsmen: “By way of furnishing a key to their arrangement, all the pieces used to be marked with the point of a diamond, and this mark indicates the tone the glass requires for such and such a part of the design. The signs most often employed were three, namely X, L, and V, for red, blue and yellow respectively, intermediate tones being shown by combinations of these letters—XL, LV, XV, with “lines of unities” placed before or after to indicate the necessary gradation in the tone.”