310 EOMAN ARCHITECTURE. Pakt I. centuries of ill-treatment and neglect, and may last for as many more without injury to its stability, but might be said of a portico which, if of wood, as Etruscan ])orticoes usually were, may easily in 200 years have required rej)airs and rebuilding. From a more careful examina- tion on the spot, I am convinced that the portico was added at some subsequent period to the rotunda. If by Agrippa, then the dome must belong to Republican times ; if by Severus it may have been, as is generally supposed, the hall of the Baths of Agrippa. i Altogether I know of no building whose date and arrangements are so singular 191. Half Elevation, half Section, of the Pantheon at Rome. Scale 50 ft. to 1 in. and SO exceptional as this. Though it is, and always must have been, one of the most jtrominent buildings in Rome, and most important iroiii its si/.c and ilcsigii, I know of no othei' building in Rome whose date or original destination it is so difficult to determine. Internally perhajts the greatest defect of the building is a want of height in the ])crpendicular part, which the dome apjiears to overpower and crush. This mistake is aggravated by the lower part being cut u]) into two stories, an attic being placed over the lower order. The ' When till' lirst fditioii of this work was written 1 bclicvtMl the rotunda to have b(!i'n added to the portieo by Sev- erus; and if this were so it would get over many of the dittieulties arisins;froin its size and the character of lis brick- work. My personal examination, how- over, has forced me very unwillingly to give up this hypothesis. It certainly is, however, very astonishing that such a vault should have been attempted at so early au age.
