[246] The photo-engraver has unfortunately turned this photograph upside down, but it is not of much consequence, as the size and thickness of the bricks of Nero can be seen just the same. The space is so narrow that it was difficult to get a photograph of it at all; but this is just one of the cases in which a photograph is of great importance, because there is nothing in which artists are so careless as in the thickness of the bricks and of the mortar between them; there is nothing in which it would be more easy to play tricks, if they wished to do so. [247] The fragment of sculpture placed upon this capital has nothing to do with it, being merely placed there by the workmen, but a photograph necessarily reproduces things exactly as they were found at the time the photograph was taken. [248] The piers of tufa are represented as transparent, to shew the insertion of the consoles in them. This insertion, with the irregularity of the plan of the tufa piers, contrasted with the mathematical accuracy of the work of the Flavian Emperors, proves that they belonged to an earlier building. [249] In other instances, the brick arches of construction appear to rest on the piers of travertine between them; but as these have been removed, and the brick walls stand equally well without them, it is evident that this is not the case. The tall piers of travertine reach the whole height of the building, to support the upper gallery. In the following plate the same remarkable construction is shewn more clearly, because in this instance the aperture left by the removal of the stone piers is visible in two storeys, and it is seen that three piers extended from the upper gallery to the ground, passing through all the other storeys. [250] In this plate the coins are taken by photograph from the originals in the British Museum. [251] Qy. Colonnade of Aqueduct, or Piscina Limaria. [252] Qy. Reservoir (_castellum aquæ_) of the time of Alexander Severus, of which there are remains. [253] For further details see the _Descrizione di Pompeii per Giuseppe Fiorelli_, Napoli, 1875, 12mo., pp. 56 and 70. All who are interested in Pompeii should have this valuable little work. THE ARCHÆOLOGY OF ROME, BY JOHN HENRY PARKER, C.B. HON. M.A. OXON., F.S.A. LOND.; KEEPER OF THE ASHMOLEAN MUSEUM OF HISTORY AND ARCHÆOLOGY, OXFORD; VICE-PRESIDENT OF THE OXFORD ARCHITECTURAL AND HISTORICAL SOCIETY, AND OF THE BRITISH AND AMERICAN ARCHÆOLOGICAL SOCIETY OF ROME; MEMBER OF THE ROYAL ARCHÆOLOGICAL INSTITUTE, MEMBRE DE LA SOCIETÉ FRANÇAISE D’ARCHÉOLOGIE, HONORARY MEMBER OF THE ROYAL INSTITUTE OF BRITISH ARCHITECTS, AND OF VARIOUS ARCHÆOLOGICAL SOCIETIES, ENGLISH AND FOREIGN. =PART VII.=