Turning eastward, and surveying the north side, we observe that this is not, like the western, a straight line, but an obtuse angle, which is bounded on the east by the Brass Mount, probably so called because brass cannon were mounted on it. At the bend is the North Bastion, a modern erection containing three tiers of casements, each pierced for five guns. At the north-east we leave the side of the Moat, and passing up through the gardens emerge opposite the Mint into the open road, which leads over that wonderful achievement of modern engineering, the Tower Bridge. But as our present business is not with it, we go down a flight of steps into Little Tower Street, on a level with the Thames. The wall on the eastern side is quite straight; and so we pass to the eastern end of the river front. This, as being the most exposed and also having the moat narrower, is fortified with five regular towers, the Develin, Well, Cradle, St. Thomas’s and Byward Towers. The Develin (_temp._ Henry III) formerly led into the precincts of St. Katharine’s. Till lately it was used as a powder magazine. The Cradle Tower is in front of what were the royal apartments, and was a gate specially for the convenience of royalty. There was in those days a portcullis, and a hoist or lift by which a boat could be lifted from the river to the level of the gateway. Hence the name “cradle,” a movable bed. Next we come to St. Thomas’s Tower, almost always called now Traitors’ Gate, from its ancient function. It was the water-gate of the Tower, and commanded the communication between the Thames and the Moat. It is in fact a barbican, probably unique, placed astride upon the Moat, which was here about 40 feet broad, and perforated by a passage leading from the river. The original name was the _Watergate_; “Traitors’ Gate” dates from the time of Queen Elizabeth. Independently of its historical associations it is really a wonderful structure, a magnificent arch, 62 feet span, with no key-stone, the stones of the two rows of the arch fitted together with perfect accuracy. The state prisoners were brought down the river in the government barge, conveyed beneath this arch to the flight of steps, by which they ascended to the gateway of the Inner Ward. Of course, like the rest of the Moat, the bed is now dry and the river walled out, but there, under the arch, are still the massive folding trellised gates, as well as the steps, the latter partially renovated, no doubt, but unmistakably showing some of the old ones which so many feet have trod. We think of the men, not only brought in as prisoners, but carried forth again to Westminster Hall for trial, and brought back so often under sentence of death, with the edge of the axe turned towards them. Not the Roman Capitol, nor the Römer of Frankfurt, nor the Bridge of Sighs at Venice can count such a list of names as Traitors’ Gate. St. Thomas’s Tower was built by Henry III, and named by him after St. Thomas of Canterbury.