| Fig. 295. | Fig. 296. | Fig. 297. | Fig. 298. | Fig. 299. |
We have already seen that single columns may be used to carry arcades of two or more orders, either by breaking their abaci into receding angles, to fit them to the orders of the arches, or by making round or octagonal abaci large enough to receive them; and such single columns may be alternated with clustered piers. There is, however, another extensive variety of pillar compounded of the two.
Fig. 300.
Fig. 301.
Let us suppose a single column supporting arches of a single order (Fig. [300]), and that we desire to extend the arches to three orders, retaining the same main bearing-shaft. We may imagine the additional orders to be super-added on all sides of the original square springer and additional colonnettes (attached or detached) added round the original bearing-shaft to receive them ([Fig. 301]). The same may be applied to an octagon, placed either angularly or in its usual position (Figs. [302], [303]).
| Fig. 303. | Fig. 302. | Fig. 304. | Fig. 306. |