Plates IX and X. Circular Plans of Large Dimensions

Plates IX and X. — Further developments of the circular plan on a large scale are given here with interest centering in the interior treatment of the dome as part of a large conception. Several types of plan have been selected for illustration, but many other variations are possible. In Nos. I and II the dome would not be expressed as a dominating external feature. These and the interior perspective view on Plate IX are taken from the Museum at Berlin. It will be seen that a highly decorative effect results from this studied arrangement of an internal peristyle and the contrast of curves at different levels. In Nos. III, IV and V the dominant motive appears both internally and externally. These have been selected to show the development of the circular plan on lines of rich simplicity. Attention has been given to circulation and direct access, the staircases and other features being introduced as external steadying features without which no circular building of large scale can be regarded as entirely satisfactory. In No. IV double columns on radial lines separate the circular hall from the ambulatory and these columns are expressed externally by pilasters directly radial on plan. The steadying features in this case consist of a tetrastyle portico connected to the external wall of the rotunda, and a square bay containing a semi-circular recess as a posterior feature. No. V shows a circular plan, consisting of eight bays internally, one of which is allocated to the entrance and staircase. The feature of the plan is the distribution of the internal composite piers. The gallery or upper ambulatory forms a prominent feature of the interior, additional height being given by an arcade supporting the dome. Externally the basement storey assumes a polygonal form of sixteen bays and the fine composition obtained by James Gibbs is suggested in the sketch reproduced in Fig. 2.