110 THE STONES OF VENICE CONSTRUCTION

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. X b and Y b 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 X b. The reader must not be angry with me for stating things so self-evident, for these are all necessary steps in a 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 Y b 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.

§ 15. I have said nothing yet of the proportion of the height of Y b to its width, nor of that of Y b and X b 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 Y b may be thus generally stated. If it look 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.

§ 16. I have also supposed Y b, when expanded from beneath X b, as always expanded into a square, and four spurs only to be added at the angles. But Y b may be expanded into a pentagon, hexagon, or polygon; and X b 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.

§ 17. We have hitherto conducted the argument entirely on the supposition of the pillars being numerous, and in a

[Version 0.04: March 2008]