We have already suggested, in Chapter IV., the probability that the immense variety of Moorish ornaments, which are formed by the intersection of equidistant lines, could be traced through the Arabian to the Greek fret.
The ornaments on Plate XXXIX. are constructed on two general principles; Nos. 1-12, 16-18, are constructed on one principle (Diagram No. 1), No. 14 on the other (Diagram No. 2). In the first series the lines are equidistant, diagonally crossed by horizontal and perpendicular lines on each square. But by the system on which No. 14 is constructed, the perpendicular and horizontal lines are equidistant, and the diagonal lines cross only each alternate square. The number of patterns that can be produced by these two systems would appear to be infinite; and it will be seen, on reference to Plate XXXIX., that the variety may be still further increased by the mode of coloring the ground or the surface lines. Any one of these patterns which we have engraved might be made to change its aspect, by bringing into prominence different chains or other general masses.
The general effect of Plate XLI. and XLI*. will, we think, at once justify the superiority we have claimed for the ornament of the Moors. Composed of but three colors, they are more harmonious and effective than any others in our collection, and possess a peculiar charm which all the others fail to approach. The various principles for which we have contended, the constructive idea whereby each leading line rests upon another, the gradual transitions from curve to curve, the tangential curvatures of the lines, the flowing off of the ornaments from a parent stem, the tracing of each flower to its branch and root, the division and subdivision of general lines, will readily be perceived in every ornament on the page.
The ornament No. 1, on Plate XLII., is a good example of the principle we contend for, that to produce repose the lines of a composition should contain in equilibrium the straight, the inclined, and the curved. We have lines running horizontally, perpendicularly, and diagonally, again contrasted by circles in opposite directions. So that the most perfect repose is obtained, the tendency of the eye to run in any direction is immediately corrected by lines giving an opposite tendency, and wherever the eye strikes upon the patterns it is inclined to dwell. The blue ground of the inscriptions and ornamental panels and centres, being carried over the red ground by the blue feathers, produces a most cheerful and brilliant effect.
The leading lines of the ornaments Nos. 2-4, Plates XLII. and XLII*., are produced in the same way as the interlaced ornaments on Plate XXXIX, above. In Nos. 2 and 4 it will be seen how the repose of the pattern is obtained by the arrangement of the colored grounds; and how, also, by this means an additional pattern besides that produced by form results from the arrangement of the colors.
Pattern No. 6, Plate XLIt., is a portion of a ceiling, of which there are immense varieties in the Alhambra, produced by divisions of the circle crossed by intersecting squares. It is the same principle which exists in the copy from the illuminated Koran, Plate XXXIV., and is also very common on the ceilings of Arabian houses.
The ornament No. 5, Plate XLIIt., is of extreme delicacy, and is remarkable for the ingenious system on which it is constructed. All the pieces being similar, it illustrates one of the most important principles in Moorish design, one which, more perhaps than any other, contributed to the general happy result, viz. that by the repetition of a few simple elements the most beautiful and complicated effects were produced.
However much disguised, the whole of the ornamentation of the Moors is constructed geometrically. Their fondness for geometrical forms is evidenced by the great use they made of mosaics, in which their imagination had full play. However complicated the patterns on Plate XLIII. may appear, they are all very simple when the principle of setting them out is once understood. They all arise from the intersection of equidistant lines round fixed centres. No. 8 is constructed on the principle of Diagram No. 2, cited on the other side, and is the principle which produces the greatest variety; in fact, geometrical combinations on this system may be said to be infinite.