That portion of the line which lies between the Tipalt and the Irthing is probably weaker than any other between Wallsend and Bowness. Not only is the ground flat, but it is destitute of the aid which copious rivers give it, both at its eastern and western extremities. Throughout the whole of this district, both barriers keep close together. Except in the neighbourhood of Rose-hill, no portion of the stone Wall remains in all this tract. The country between the Tipalt and the Solway is characterized by a number of diluvial hills, not unfrequently resembling barrows. To the south of Brampton, they are so numerous and so nearly uniform in size and shape as to suggest to the playful imagination the idea of their being gigantic mole-hills. The occurrence of these in the line of the Barrier must have caused some trouble to the engineer of the Wall. The difficulty, however, was overcome. The first hill of this description that we meet with, occurs immediately westward of the point where the Newcastle and Carlisle railroad crosses the mural line. The Wall unhesitatingly ascends it on the one side, and descends it on the other, though it would scarcely have described a larger arc had it gone round its base. [Sidenote: VALLUM AT WALLEND.] About half-a-mile onward is a small village, called Wallend. The earth-works are, for a short distance, in an admirable state of preservation; nowhere else is the Vallum seen to greater advantage. A peculiarity in the relative position of the Wall and Vallum will here force itself upon the attention. The Wall, which, for the larger portion of its course, stands considerably above the Vallum, now takes a lower level, and for nearly the whole space between this point and the Irthing, is completely commanded by the earthen ramparts. The following diagram will give a general idea of the country, and of the mutual relation between the two structures. Had the Wall (A) and Vallum (B) been independent undertakings, this arrangement would not have been adopted. The earth-works ascribed to Hadrian having been found inefficient, would have been relentlessly cut in upon by the officers of Severus, who would doubtless have planted the Wall in those positions which were naturally the strongest, irrespective of any prior work. As it is, to give the Vallum the advantage of an eminence in resisting a southern foe, the Wall relinquishes a portion of the acclivity which it might with advantage have taken. [Illustration: Section of Works near Wallend] [Sidenote: CHAPEL HOUSE.]