§ XIV. If the reader chooses to consider this spur as an æsthetic feature altogether, he is at liberty to do so, and to transfer what we have here said of it to the beginning of Chap. XXV. I think that its true place is here, as an expression of safety, and not a means of beauty; but I will assume only, as established, the form e of Fig. XII., which is absolutely, as a construction, easier, stronger, and more perfect than b. A word or two now of its materials. The wall base, it will be remembered, was built of stones more neatly cut as they were higher in place; and the members, Y and X, of the pier base, were the highest members of the wall base gathered. But, exactly in proportion to this gathering or concentration in form, should, if possible, be the gathering or concentration of substance. For as the whole weight of the building is now to rest upon few and limited spaces, it is of the greater importance that it should be there received by solid masonry. Xb and Yb are therefore, if possible, to be each of a single stone; or, when the shaft is small, both cut out of one block, and especially if spurs are to be added to Xb. The reader must not be angry with me for stating things so self-evident, for these are all necessary steps in the chain of argument which I must not break. Even this change from detached stones to a single block is not without significance; for it is part of the real service and value of the member Yb to provide for the reception of the shaft a surface free from joints; and the eye always conceives it as a firm covering over all inequalities or fissures in the smaller masonry of the floor.
§ XV. I have said nothing yet of the proportion of the height of Yb to its width, nor of that of Yb and Xb to each other. Both depend much on the height of shaft, and are besides variable within certain limits, at the architect’s discretion. But the limits of the height of Yb may be thus generally stated. If it looks so thin as that the weight of the column above might break it, it is too low; and if it is higher than its own width, it is too high. The utmost admissible height is that of a cubic block; for if it ever become higher than it is wide, it becomes itself a part of a pier, and not the base of one.
§ XVI. I have also supposed Yb, when expanded from beneath Xb, as always expanded into a square, and four spurs only to be added at the angles. But Yb may be expanded into a pentagon, hexagon, or polygon; and Xb then may have five, six, or many spurs. In proportion, however, as the sides increase in number, the spurs become shorter and less energetic in their effect, and the square is in most cases the best form.
§ XVII. We have hitherto conducted the argument entirely on the supposition of the pillars being numerous, and in a range. Suppose, however, that we require only a single pillar: as we have free space round it, there is no need to fill up the first ranges of its foundations; nor need we do so in order to equalise pressure, since the pressure to be met is its own alone. Under such circumstances, it is well to exhibit the lower tiers of the foundation as well as Yb and Xb. The noble bases of the two granite pillars of the Piazzetta at Venice are formed by the entire series of members given in Fig. X., the lower courses expanding into steps, with a superb breadth of proportion to the shaft. The member Xb is of course circular, having its proper decorative mouldings, not here considered; Yb is octagonal, but filled up into a square by certain curious groups of figures representing the trades of Venice. The three courses below are octagonal, with their sides set across the angles of the innermost octagon, Yb. The shafts are 15 feet in circumference, and the lowest octagons of the base 56 (7 feet each side).
§ XVIII. Detached buildings, like our own Monument, are not pillars, but towers built in imitation of Pillars. As towers they are barbarous, being dark, inconvenient, and unsafe, besides lying, and pretending to be what they are not. As shafts they are barbarous, because they were designed at a time when the Renaissance architects had introduced and forced into acceptance, as de rigueur, a kind of columnar high-heeled shoe,—a thing which they called a pedestal, and which is to a true base exactly what a Greek actor’s cothurnus was to a Greek gentleman’s sandal. But the Greek actor knew better, I believe, than to exhibit or to decorate his cork sole; and, with shafts as with heroes, it is rather better to put the sandal off than the cothurnus on. There are, indeed, occasions on which a pedestal may be necessary; it may be better to raise a shaft from a sudden depression of plinth to a level with others, its companions, by means of a pedestal, than to introduce a higher shaft; or it may be better to place a shaft of alabaster, if otherwise too short for our purpose, on a pedestal, than to use a larger shaft of coarser material; but the pedestal is in each case a make-shift, not an additional perfection. It may, in the like manner, be sometimes convenient for men to walk on stilts, but not to keep their stilts on as ornamental parts of dress. The bases of the Nelson Column, the Monument, and the column of the Place Vendôme, are to the shafts, exactly what highly ornamented wooden legs would be to human beings.
§ XIX. So far of bases of detached shafts. As we do not yet know in what manner shafts are likely to be grouped, we can say nothing of those of grouped shafts until we know more of what they are to support.
Lastly; we have throughout our reasoning upon the base supposed the pier to be circular. But circumstances may occur to prevent its being reduced to this form, and it may remain square or rectangular; its base will then be simply the wall base following its contour, and we have no spurs at the angles. Thus much may serve respecting pier bases; we have next to examine the concentration of the Wall Veil, or the Shaft.
CHAPTER VIII.
THE SHAFT
§ I. We have seen in the last Chapter how, in converting the wall into the square or cylindrical shaft, we parted at every change of form with some quantity of material. In proportion to the quantity thus surrendered, is the necessity that what we retain should be good of its kind, and well set together, since everything now depends on it.
It is clear also that the best material, and the closest concentration, is that of the natural crystalline rocks; and that, by having reduced our wall into the shape of shafts, we may be enabled to avail ourselves of this better material, and to exchange cemented bricks for crystallised blocks of stone. Therefore, the general idea of a perfect shaft is that of a single stone hewn into a form more or less elongated and cylindrical. Under this form, or at least under the ruder one of a long stone set upright, the conception of true shafts appears first to have occurred to the human mind; for the reader must note this carefully, once for all, it does not in the least follow that the order of architectural features which is most reasonable in their arrangement, is most probable in their invention. I have theoretically deduced shafts from walls, but shafts were never so reasoned out in architectural practice. The man who first propped a thatched roof with poles was the discoverer of their principle; and he who first hewed a long stone into a cylinder, the perfecter of their practice.
§ II. It is clearly necessary that shafts of this kind (we will call them, for convenience, block shafts) should be composed of stone not liable to flaws or fissures; and therefore that we must no longer continue our argument as if it were always possible to do what is to be done in the best way; for the style of a national architecture may evidently depend, in great measure, upon the nature of the rocks of the country.
Our own English rocks, which supply excellent building stone from their thin and easily divisible beds, are for the most part entirely incapable of being worked