Seven or eight courses of facing-stones and the {140} projecting foundations clearly visible gave me great satisfaction as I continued my way. The wild-flowers were very wonderful, the yellow cistus, or rock-rose, growing all over the Wall, with its delicate blossoms and dark silver-lined leaves. Tall foxgloves sent up their spikes of nodding blossoms, like stately Roman Emperors, clothed in the imperial purple, while rosy wild thyme and blue speedwell prostrated themselves, like humble courtiers, at their feet. Every writer on the Wall has, I believe, to do his duty in repeating Sir Walter Scott's verses about the flowers that grow on it--once, at least. _His_ flowers came from the Nine Nicks, it is said, and not from this particular spot, but this seems a suitable opportunity for quoting his lines: "TO A LADY WITH FLOWERS FROM THE ROMAN WALL" "Take these flowers, which, purple waving, On the ruined rampart grew. Where, the sons of freedom braving, Rome's imperial standards flew. Warriors from the breach of danger Pluck no longer laurels there: They but yield the passing stranger Wild-flower wreaths for beauty's hair." As the ground dips down to the next gap, Cawfields mile-castle is seen on the slope of the hill. This was the first mile-castle to be opened, by Mr. John Clayton, in 1848. In the following year Dr. Bruce took a party of pilgrims along the Wall, and {141} they christened this gap between Cawfields mile-castle and quarry, "The Pilgrims' Gap." The masonry of both northern and southern gateways is massive, and in splendid condition. It should be studied from north of the Wall also. The size of this mile-castle is 63 feet by 49 feet. The pivot-holes of the gates are very clearly seen. It was now beginning to rain, and by the time I had got through the gap and into the Cawfields quarry yard it was coming down heavily, so I sheltered in the shed of the quarry, which is close by the Haltwhistle Burn, known as the Caw Burn between this point and its source. At a bend of the stream are the remains of a Roman water-mill, such as is described by Vitruvius, writing early in the first century. Third-century pottery has been found there, and a coin of Trajan; also the remains of the water-shoot. The mill-stones are in Chesters Museum. A little defensive rampart ran across to protect it, from river to river. We are now also near the Haltwhistle Burn Fort, which is not a mere temporary Roman camp, as was supposed, but a permanent fort, with two branch roads leading from the gates to the Stanegate, which here crosses the burn. The headquarters building, the barracks and other buildings, and the oven were excavated in 1907 by the late Mr. J. P. Gibson and Mr. F. G. Simpson. The fort {142} was dismantled when Æsica, the next fort on the Wall, was built.