attritive

The answers were always attritive and painful.

The reader, by passing half a bushel of the common shells of our shores through a barley-mill, as a preliminary operation in the process, and by next subjecting the broken fragments thus obtained to the attritive influence of the waves on some storm-beaten beach for a twelvemonth or two, as a finishing operation, may produce, when he pleases, exactly such a water-worn shelly debris as mottles the blue boulder-clays of Caithness.

The projecting edge of some fossil-charged bed had been struck, mayhap, by an iceberg, and dashed into ruins, just as the subsiding land had brought the spot within reach of the attritive ice; and the broken heap thus detached had been shortly afterwards covered up, without mixture of any other deposit, by the red boulder-clay.

The Giants' Graves—to borrow from the children of the place—occur on the steep slopes of the old coast line, or in the sides of ravines, where the clay, as I have said, had once presented a precipitous front, but had been gradually moulded, under the attritive influences of the elements, into series of alternating ridges and furrows, which, when they had flattened into the proper angle, the green sward covered up from further waste.

The underlying bed is composed of broken fragments of the rocks below, crushed, as if by some imperfect rudimentary process, like that which in a mill merely breaks the grain; whereas, in the bed above, a portion of the previously-crushed materials seems to have been subjected to some further attritive process, like that through which, in the mill, the broken grain is ground down into meal or flour.