Before the Beefeater and the escort have marched twenty yards, further obstructions delay their progress. These fresh obstacles appear in the forms of the vigilant sentinels at the Jewel House and at the Traitors’ Gate; which latter was once used for the admission of ‘traitors’ brought down the river from Westminster. In succession, each of the soldiers challenges in the same way as his comrade at the Main Guard. And when the Beefeater has satisfactorily answered both men, the party moves onward for some little distance, and is a fourth time brought to a halt by a sentry at the Byward Gate. This gate is on the inner margin of the now dry ditch that encircles the Tower. It stands under an arch, which is surmounted and flanked by turrets or fortifications of a long obsolete design. Besides the soldier alluded to, a Yeoman is at all hours on duty at this point. He is always to be found in an apartment, with a quaint vaulted roof, close by the gate: the place has obviously once been the quarter of a regular military guard. The sentry here having been satisfied as to the character of the escort, it passes on, traverses a causeway leading across the moat, and reaches the Spur Guard. There, of course, it is stopped by a sentry belonging to that body; and the Keys are eventually saluted by this soldier, as well as by the guard of which he forms a unit. And now, after all those impediments have been overcome, the Barrier Gate is at length approached, its custodian having been appeased in the stereotyped manner. The Barrier Gate is the outermost gate of the Tower, and it is necessarily the first to be locked. As already noticed, the warder marches a little in front of the escort. When he is within some fifteen or twenty paces’ distance from the gate, he halts. Then the men composing the escort advance, and under the superintendence of the sergeant, line the sides of the road, facing inwards towards its middle. The Beefeater, with considerable solemnity of demeanour, now walks up between the ranks, selects the appropriate key, and locks the gate, which in the meantime has been closed by a corporal. This operation accomplished, and having given the gate a shake, to assure himself of its being properly fastened, the Beefeater resumes his position a few yards away, passing as before between the lines of soldiers. Arms are presented to the Keys, both when they are proceeding to the gate and when they are retiring from it, by word of command from the sergeant; for the officer remains behind with the Main Guard.