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Another favourite misuse of ropes is to lash them round blocks of stone which have to be dragged, and thus cut the rope into scraps by wearing on the ground. Ropes can generally be put round the sides of a stone, and kept in place by some old scraps passing beneath.

Tracing walls.

One of the most careful kinds of work, to which only good men can be trained, is that of tracing out unbaked brick walls buried in rubbish. The surrounding earth is derived from the crumbling and washing down of the earthen wall, and therefore it is indistinguishable from the average of the bricks themselves. Hence, if the bricks are uniform in colour, and the mud mortar is like them, the building and its débris are all alike. The best way to examine brickwork is by scraping a face of the wall, and then peeling it quite clean with a dinner-knife; such a clean smooth surface seen in shadow will show whatever can possibly be made out of the differences of colour and texture. Vertical joints are worth far more than horizontal, as often fallen bricks may lie as if built together. If possible the joints should be observed by differences of colour, and the bricks measured for comparison with others; as the sizes vary from 7 inches to 2 feet in length, and but seldom range over half an inch in any one building period, the size will go a long way in showing a connection of age. If the bricks cannot be distinguished even after leaving the face to dry for some days, the earth should be searched by pecking with a trowel or knife to see if there is dirt in it: only in late times are pottery chips found usually in bricks, and charcoal scraps are very rare, hence pottery and charcoal almost prove the earth to be mere wash and rubbish. The clearing back of dirty earth to a vertical face of clean clay is a satisfactory evidence of a wall. But sometimes the filling is so clean that there is no difference between it and the wall. Then the relative hardness will often serve to distinguish one from the other; and this is a main means of discrimination by the workmen, who will often tell a wall entirely by the touch under the pick. Failing all these tests, and the strata of dirt beds, the film of stucco on the wall face will sometimes show up, but may leave a doubt as to which side is the wall. In the last resource the stuff should be searched with a magnifier to see the hollows left by decomposed straw dust: in kneaded brick these hollows lie in every direction; in blown dust and wash they lie nearly all horizontal. It is often needful to spend half-an-hour testing and tracing out the line of a wall, fixing the face and the top and base of it; and such work may give the only evidence of a temple or important building.