holmes] 



ABORIGIlSrAL AMERICAlSr ANTIQUITIES PART I 



355 



gions instead of the mouthpiece the top of the shaft was held by an 

 assistant, and as much pressure applied as was needed (fig. 220). 

 The bow drill is closely related to the strap drill. The headpiece 



is held in position with the left hand, while the strap 

 Bow Driu is attached to the two ends of the bow and after 



wrapping around the shaft, is revolved by a back- 

 ward and forward movement of the bow held in the right hand 

 (fig. 221). 



Fig. 220. Primitive method of drilliug. 



The disk drill, which apears to be confined to the tribes of Cali- 

 fornia, is a variant of the pump drill. The fixed 

 Disk Drill disk of the pump drill is omitted, and a wide 



movable disk takes the place of the movable cross- 

 piece. Through holes in opposite margins of the disk thongs are 

 passed and attached, one end to the top of the shaft and the other to 



Fig. 221. I'rimitive method of drilling. 



the base near the drill point. The revolving motion is started by 

 turning the disk until the thongs are twisted around the shaft, be- 

 coming taut. The disk is then released and pressed suddenly down- 

 ward, when the strands unwind, revolving the shaft, the momentum 



