It may be that the possession of such antique relics, and the long-established practice of re-using them, may have suggested the use of small columns for such purposes; indeed, it is curious that in the case of the Mosque of Touloun, just alluded to, as a very early instance of the use of colonnettes, there is a tradition that the architect, who was a Christian, was imprisoned for refusing to use the columns torn
Fig. 294.—Cloisters of St. Paul without the Walls, Rome.
from desecrated churches, which had been a condition prescribed to him, and only consented to proceed with the work on the withdrawal of this order. Whether or not, this custom originated the feature under consideration, I think that it is one which belongs essentially to a derivative style, and would hardly have come into existence in a style of architecture not aided by traditions of the past. The Romans themselves, as is proved by their mural paintings, seem to have indulged in the use of thin columns (possibly of metal), for buildings not demanding massive dignity; and it is just possible that in their domestic architecture some suggestions of this use of such pillars might have existed; and certainly among Mediæval works, in none are they more charmingly introduced than in the cloisters of St. Paul without the Walls, and St. John Lateran, at Rome, whose details are much more Classic than Gothic ([Fig. 294]).
In our Norman buildings colonnettes are for the most part built in the solid of the piers, which would suggest that they are not there in the earliest stage of their use.
The principle once adopted, there seems no limit to the variety of which it is capable. Shafts may be substituted for all of the arch-orders, or for such only of them as may be desired.
Where the arch consists of more than two orders, a half-column of larger size may be made to support two or more, and smaller ones may flank them carrying single orders ([Fig. 295]). Where, again, the lower order is wide in its soffit, it may be carried either by a large semi-column (Fig. [296]) or by coupled colonnettes ([Fig. 297]); and where there are three orders, the same may be applied to the front, bringing the pillars to a uniform design on all of its sides (Figs. [298], [299]).
