LINES CUT BY STEEL AND FLINT INSTRUMENTS.
As to the steel-cut appearance of the lines, Dr. Brinton says: "The lines on the Lenape Stone are obviously cut with a steel instrument, making clean incisions, deepest in the centre and tapering to points, quite different from the scratch of a flint point"; and Dr. M. E. Wadsworth thinks that "the depth and regularity of the carvings indicate that they were made with some dulled steel tool like an awl." On the other hand Mr. J. E. Iddings does not know whether it is possible thus to distinguish the work of steel and flint instruments, and a series of experiments with the microscope and steel and flint points has induced the writer to believe that lines cut on a similar stone by "a dulled steel instrument" and a flint arrow-point cannot be distinguished after both have been washed and scrubbed.
The appearance of such lines would of course depend much upon the sharpness of the flint or steel point, the kind of stone used, and whether the lines were cut by one or by a series of strokes. The single scratch of a scissors point on a shale tablet of similar hardness makes an incision in shape like the letter V; that of either an awl or flint arrow-head one like the letter U; while any line made by either instrument and consisting of a series of strokes will have its bottom furrowed by parallel grooves, as in the case of the large lines on the Lenape Stone.
The fresh flint-cut grooves, however, when separately examined with the microscope, exhibit many faint scratches running along the furrow, not so conspicuous in the steel incisions, yet a few applications of soap, water, and a scrubbing-brush efface these scratches in both cases, and render the surface of the grooves indistinguishably alike and in appearance similar to the now polished incisions upon the Lenape Stone. In other respects the scratch of the arrow-head can be made of equal depth, clearness, and regularity, the flint point, if held carefully, not appearing to tear the edges of the incision more than the awl. Moreover, we can cause the flint-cut line to "taper to a point" or not, as we choose.