460 CHINESE ARCHITECTURE. BOOK IX. columns, as also the lower storey. The construction inside is of a very extraordinary kind; at the level of the upper part of the second roof carved beams are tenoned into the four columns, over which, between each are provided two other columns, forming a sort of attic storey, to support the roof and the internal dome. Though not indicated in the woodcut, the four great columns, which rise to the roof, are visible out- side, between them and at the back of the attic columns the outer case of the drum is constructed with curved timbers, and there are no windows as shown. As the horizontal beams, or plates, are only tenoned into the columns, and the weight they have to carry is greater than such beams could carry, it has been found necessary to provide other beams underneath, on which they rest, and these beams are sunk into others crossing from the four great columns to four of those of the aisle or clerestory an arrangement of a most complicated character. The interior of the dome is horizontally subdivided into three parts, the lower decorated with an assemblage of brackets forming a frieze, the middle part panelled and the centre sunk with a deep coffer ; all the woodwork is gilded, the upper part of the columns with patterns in imita- tion of damask work. The Temple of Heaven is said to have been erected about the year 1420 A.D., and originally the roof of the upper storey was covered with blue tiles, that of the middle one with yellow tiles, and of the lower one green, but the Emperor Kien-lung (1736-1796) changed them all to one colour of a deep ultramarine blue. As this temple is said to have been burnt down in 1860, it is probable that the existing building is only a copy. A second circular temple in the enclosure of the Temple of Heaven, the Huang-Chiang- yen, has one roof only, and the dome inside carried on eight columns is similarly decorated with two beaded friezes, and panelled above with a circular plaque in the centre. There is a third example of a circular dome in the Chung-ho-t'ien, the Hall of Central Peace, in which the dome is decorated in the same way, but is much finer in design and decoration than the other two, and a fourth in the Temple of Agriculture of which an excellent lithograph is published in vol. xvii. of the 'R.I.B.A. Transactions, 1866-67.' The bracket frieze found in these circular temples exists also in the rectangular ones ; in both cases their origin can be traced to the constructive forms evolved in the support of the widely projecting eaves, they are employed also in the deeply coffered ceilings of some of the halls of the Imperial Palace, such as those of the Chio-tai Chung -ching, and other halls of reception and audience.
