Since that period, few important discoveries have been made. In cutting the crest of the hill in front of the Castle for one of the piers of the Railway viaduct, a small stone figure of Mercury, represented in the adjoining wood-cut,[62] was found. It is preserved, among other antiquities, in the Museum in the Castle. Between the years 1840 and 1844, the White-friar-tower and the contiguous portions of the Town-wall of Newcastle were removed. Two Roman altars were discovered, which are now in the possession of the Society of Antiquaries, Newcastle-upon-Tyne. One of them is destitute of an inscription, and the other seems to bear the word SILVANO. Several coins of the Roman and mediæval age were picked up in its immediate vicinity. The Roman coins were of both the upper and the lower empire. From the manner in which the pieces of the middle and ancient periods were commingled, a thing of rare occurrence, it may be inferred that the tower was formed out of Roman materials, and that the Roman coins were re-imbedded without being noticed, whilst the workmen inadvertently added Nuremberg tokens and other contemporary pieces to the numismatic treasures of the spot. But, perhaps, the structure which gave name to PONS ÆLII affords the most interesting foot-prints of Roman occupation in Newcastle. [Sidenote: THE BRIDGE OF ÆLIUS.] Horsley received sufficient evidence to convince him, that a Roman road had gone from the south bank of the Tyne to Chester-le-street, and thence to the south of England. A bridge was necessary to conduct the road across the river. In 1771, a flood having carried away several of the arches of the bridge which then existed, and materially damaged the rest of the structure, it was found necessary to erect a new one. In removing the old piers the distinguishing characteristics of Roman masonry were observed; and the workmen were led to believe that the arches of the mediæval structure had been placed upon the foundations which Hadrian laid. Several piles of fine black oak, which had supported the foundation, were drawn out of the bed of the river, and found to be in a state of excellent preservation.[63] [Sidenote: COINS FOUND IN THE BRIDGE.] The coins that were found imbedded in the piers give decided evidence of the Roman origin of the structure. To some of these, in the possession of George Rippon, esq., of Waterville, North Shields, I have had access; they are here represented. [Illustration] _Obv._—HADRIANUS AUGUSTUS, CONSUL TERTIUM. PATER PATRIÆ. Bare head of Hadrian. _Rev._—GERMANIA. The province personified as a female standing. In her right she holds a lance; her left hand rests upon a German-shaped shield. [Illustration] _Obv._—IMPERATOR CÆSAR TRAJANUS HADRIANUS AUGUSTUS. Laureated head of Hadrian.