The simplest type of central building is a circular edifice.
Pl. LXXXIV, No. 9. Plan of a circular building surrounded by a colonnade.
Pl. LXXXIV, No. 8. Elevation of the former, with a conical roof.
Pl. XC. No. 5. A dodecagon, as most nearly approaching the circle.
Pl. LXXXVI, No. 1, 2, 3. Four round chapels are added at the extremities of the two principal axes;—compare this plan with fig. 1 on p. 44 and fig. 3 on p. 47 (W. P. 5b) where the outer wall is octagonal.
Group II.
Domes rising from a square base.
The plan is a square surrounded by a colonnade, and the dome seems to be octagonal.
Pl. LXXXIV. The square plan below the circular building No. 8, and its elevation to the left, above the plan: here the ground-plan is square, the upper storey octagonal. A further development of this type is shown in two sketches C. A. 3a (not reproduced here), and in
Pl. LXXXVI, No. 5 (which possibly belongs to No. 7 on Pl. LXXXIV).