Frederich von Schlegel has described architecture as a frozen music; and in truth both these arts repose on a harmony of relations, which admit of being referred to number, and are consequently readily grasped in their fundamental characteristics. In our own case the fundamental determinant for these essential traits and their simple, more serious and imposing, or more charming and elegant relations is supplied by the dwelling-house, that is, walls, columns, beams brought together in the wholly crystalline forms of scientific deduction. What the relations are we are not permitted to reduce to the bare determinants of number and measure. But an oblong, quadrilateral figure with right angles is more pleasing than a square, because in the case of the oblong we are more thus affected both by equality and inequality[80]. If the one dimension, namely breadth, is half as large as the other, we have a relation which pleases; with an oblong which is long and narrow the reverse is the case. Along with this the mechanical relations of support and being supported must likewise be maintained in their genuine measure and law; a heavy entablature, for instance, cannot rest on slender and delicate columns, or conversely great structures be prepared in order after all to lay on them something very light. In all these mutual relations, such as that of the breadth to the length and height of the building, the height of the columns to their thickness, the intervals and number of the columns, the character and variety or simplicity of decorations, the size of many plinths, borders, and so forth, a secret principle of rhythm[81] prevails among the ancients, which the instinct of the Greeks before all others has discovered; from which he may no doubt now and again deviate in points of detail, but the fundamental relations of which he is in general bound to preserve in order that he may not fall away from beauty. 2. THE FUNDAMENTAL DETERMINANTS OF ARCHITECTURAL FORMS TAKEN SEVERALLY (_a_) We have already alluded to the old controversy whether the material of wood or stone is to be accepted as the point of departure in building, and whether also it is from this difference of material that the architectural types proceed. For the real art of building at least, in so far as it lays emphasis on the aspect of ultimate purpose and elaborates the fundamental type of the dwelling on the lines of beauty we may accept wood as the more original of the two.