OBSERVATIONS ON STONE-CHIPPING. S79 



has to be done will be seen. To attemi)t to do this and to throw off long 

 chips from tfie sharp edge of the flake would prove a failure, as its 

 sharp edge would either crumble away or it would cut and injure the 

 point of the bone flaker without throwing off" the desired chip or fluke. 

 Experience has taught the operator the best shape of edge to apply the 

 pressure to accomplish his object, and it has also taught him how to 

 reach it in the simplest possible way. A spoon-shaped hollow on the 

 top of a flattened log, or even a gutter or groove cut in it, furnishes the 

 means of holding the flake firmly, the raised or high side jflaced in tbe 

 hollow, the flat side up ; with the ends of the fingers of his left hand 

 pressed on it he holds it firmly, while with his right hand a downward 

 pressure is given by the flaking tool which breaks off chips with a fract- 

 ure of about 45 degrees from the flat surface, leaving the edge in the 

 best possible shape for future work, and that is the condition of these 

 cache flakes as they are found. 



In old times, before the invention and introduction of planing and 

 shaping machines to work metals, the first and most important lesson 

 taught to the machinist's apprentice was the use of the hand-hammer 

 and cold-chisel. When an outer shell was to be removed from a metal 

 casting and its surface left in condition to be finished by file or scraper, 

 the smoothness and regularity of that surface was essential, not only 

 for economy in working, but accuracy of the file finish. The apprentice 

 was taught to hold his cold-chisel and so direct the strokes of his ham- 

 mer that when a chip was started the chisel should hold to it, and not 

 be allowed to cut too deep or slip and fly out, leaving a shape that is 

 difficult to start a fresh cut without leaving ridges or cutting deeper, 

 in either case causing additional labor for the finisher. 



To a practical mechanic the examination of such a flint workshop as 

 I have described — its waste chips to the partly worked flakes, the roughed 

 out blocks, and the finished implements — reveal a line of workmanship 

 so clear that it can be followed to the production of the same results. 



The handling of the tool and flake to form an arrow-point is as mucli 

 an act requiring exactness and precision as the handling the cold-chisel 

 and hammer is to the machinist. The first chip thrown oft is analogous 

 to the first starting work of the cold-chisel ; it is the text that must be 

 adhered to to the end of the chapter. Holding the flake in such position 

 that commencing at what is intended for the point of the intended work, 

 the pressure with the flaking point is brought to bear close to the edge 

 of the 45 degrees angle and at right angles to it ; the result is a flake 

 thrown off inclining towards the stem end of the arrow-point. In sec- 

 tional sketch Fig. 4 from a to a' shows the 45 degrees angle left hy the 

 first rough shaping from c to c' the direction of the first chip thrown oft". 

 The seat left by this chip when thrown oft" is concave on the edge of the 

 flake, the advance corner of which is the seating point for the tool to 

 throw off the next chip, which does not entirely obliterate the concave 

 of the first, and the following chip leaves a serrated edge, the chips or 



