No. =490= is an example of a dated brick--_Imp. Antonino II (= iterum) et Br(u)ttio Co(n)s(ulibus)_ _i.e._, 139 A.D. The stamp was first engraved by error with the name of Balbinus, consul of 137 A.D., and afterwards corrected by re-engraving +RTTIO+ on +ALBIN+. No. =491= refers to the _portus_, _i.e._, the depot of Licinius. Many of the bronze accessories of building are shown here, such as two pairs of bronze door-knockers from Syria (No. =492=). The bronze dowels (No. =493=) were employed for fastening together stone sections, such as the drums of columns. They are often in the form of truncated cones placed base to base, the thickest part being thus in the position where the strain was greatest (fig. 203_a_). Other dowels from the Mausoleum at Halikarnassos are in the form of bronze cylinders in collars of bronze, rigidly fixed by three key-pieces. The cylinders were set in the great stone which closed the entrance of the Mausoleum, and were intended to drop half their length into the corresponding sockets in the lower sill of the entrance (Nos. =494-495=). [Illustration: FIG. 203.--BRONZE DOWEL AND DOOR-PIVOT (NOS. 493, 496). 1:2.] A series of bronze coverings (No. =496=) for the pivots of doors reminds us of the fact that in ancient times most of the doors worked on a different principle from our own. The bronze-covered pivots (fig. 203_b_), rigidly fixed to the door by a key-piece, turned in bronze sockets(_c_) fitted into the lintel or threshold. This arrangement explains the allusions to the grating of doors met with in ancient writers.[53] Hinges of the modern type were, however, well known. Examples are to be seen in Cases 47, 48, among them a hinge with the fragments of the wood, to which it was originally attached, still adhering (No. =497=). Towards the end of the Republic and under the Empire the Romans devoted much attention to the adornment of their buildings, public and private. For this purpose marbles of every variety were imported from all parts of the world, while an elaborate system of wall-painting was also developed. Mamurra, an officer of Julius Caesar, is said to have been the first to veneer the walls of his house with marble. A few selected examples from the Tolley collection of polished specimens of the materials used in ancient Rome are here exhibited (No. =498=). The whole collection comprises some 700 specimens, so that we cannot be surprised that Pliny declines to enumerate the varieties known in his day, on account of the vastness of their number.[54] The simpler building materials used at Rome were, besides the tiles or bricks already mentioned, the hard limestone rock known as travertine and the volcanic tufa and peperino. A specimen of the last is shown here.