354 



BUREAU OF AMEEICAlSr ETHNOLOGY 



[bdlu 60 



use by the aborigines, altliouiili it may not now be possible to deter- 

 mine whether or not they ^Yere of recent introduction. These imple- 

 ments are known as the pump, strap, bow, and disk drills. 



The pump drill consists of a shaft which passes through a disk 

 of stone, pottery, or wood, and a crosspiece through 

 Pump Drill which the shaft also runs. To each end of the cross- 



piece is attached a cord or thong having sufficient 

 plsij to allow it to pass over the top of the shaft, permitting the 

 crosspiece to reach close to the disk. In setting the device in motion 

 the disk is turned to wind the string about the shaft; this raises the 

 crosspiece. By pressing down quickly upon the crosspiece, the 

 wrapped end of the string unwinds and the shaft is made to revolve, 

 the disk thus ac(|uiring sufficient momentum to rewind the string the 

 nu/inent the pressure on the crosspiece is removed. By successive 

 pressure and release the reciprocal movement is kept up (fig. 218). 



Fig. 218. Primitive metliod of drilliiu 



Fig. 219. I'limitivc method of drilling. 



The speed attained by this drill is much greater than that of the 

 bow or the strap drill and has the advantage that one hand is left 

 free to hold the object to be drilled. 



The strap drill was in use among the Eskimo and Aleuts in early, 

 jiossibly in pre-Columbian, times. The shaft is kept 

 strap Drill ill position by means of a headpiece of wood, which 



is held between the teeth, as well illustrated in the 

 drawing (fig. 219). A strap or thong is wound once around the shaft, 

 one end being held in each hand, and is pulled alternatcl}' to the 

 right and left, revolving the shaft. The thong was sometimes fur- 

 nished with a hand piece of wood, bone, or ivory, to give a firmer grip. 

 The chief advantage of this contrivance was that pressure could be 

 regulated by pressure of the teeth on the mouthpiece. In some re- 



