394 



DRILLING IN STONE WITHOUT METAL. 



M(J.4:. 



the stick and coiled around the stick, as indicated in the drawing. The boAV is 

 then seized with both hands and pressed downwards with a violent jerk> This 

 motion nncoils the string and revolves 

 the shaft towards the left, Init by the 

 action of the fly-wheel the string is 

 coiled again around the shaft in a re- 

 verse manner, and the bow drawn up 

 again. A second jerk at the bow causes 

 the shaft to revolve tow'ards the right, 

 and by continuing this manipulation it 

 is alternately swung around in opposite 

 directions. The operator has it alto- 

 gether in his power to work the appa- 

 ratus slowly or rapidly, and, of course, 

 with coiTesponding effect ; but it re- 

 quires some practice to use it in the 

 proper manner. 



The stone selected by mc for the ex- 

 periment is a flat, oval piece of diorite, 

 of great hardness, not quite seven inches 

 long, about five inches wide, and in the 

 middle part one inch and three-eighths 

 (a little over 3.5 centimeters)'thick. I 

 chose purposely that kind of stone, be- 

 cause it is the same of which the ancient 

 inhabitants of Europe very often made 

 their pierced implements. It is both 

 hard and tough. These qualities were 

 likewise appreciated by the North American aborigines, who used diorite exten- 

 sively as the material for their tomahawks, large chisels, and pestles. The stone on 

 which I operated is so hard that the point of a well-tempered penknife produces no 

 scratch on its surface, but merely a metallic streak. The material used in drilling 

 was a sharp quartz sand of middle grain, such as is employed in marble-yards ; for a 

 short time I also tried emery, but finding that it was not more effectual than sand, I 

 continued to apply the latter. In order to render a beginning of the perforation pos- 

 sible, I tied a small square piece of board in which I had cut around hole, correspond- 

 ing to the lower diameter of the drilling-stick, with a string to the stone, just above 

 the place where the bore was to be conrmenced. Without this contrivance, which 

 I had to retain during the whole drilling process, the stick would constantly have 

 slipped out of the hole. After these preparations I could begin the W(n-k, which 

 was not very fatiguing, but tedious beyond description, taxing, in fact, my patience 

 to the utmost degree. I never could endure the work for more than two^ hours 

 in succession, and sometimes I laid the stone aside for weeks and months, until 

 I had mustered sutlicient energy to resume the labor. Thus it took two 3'ears 

 before I succeeded in piercing the stone. I cannot exactly state how many 

 hours I devoted to the work, but by measurement I obtained the I'esult that two 

 hours of constant drilling added, on an average, not more than the thickness of 

 an ordinary lead-pencil line to the depth of the hole. The work would have 

 advanced with incomparably greater speed, if I had selected a softer stone, ser- 

 pentine, for instance, instead of the hard diorite ; it was, however, my object to 

 try the experiroent on a hard mineral substance. Every five or six minutes the 

 bore had to be cleaned by immersing the stone in water, the sand being In' that 

 time perfectly ground, and forming, in connection with the water and the j^arti- 

 cles of wood rubbed from the stick, a sort of paste, which was no longer ser- 

 viceable for drilling. The quantity of sand introduced after every cleaning was 

 about etpial to the contents of a teaspoon. The shortening of the drilling-stick, 



