932 



REPORT OF NATIONAL MUSEUM, 1897. 



be rhomboidal, the two loiiij sides being the width, and tlie two short 



sides or edges beinj^: the thickness of the bhule. 



It was for a long time believed that these 

 bevel-edged arrowheads were simply freaks 

 of the workmen, aud were without sigiiitica- 

 tion or intention for particular purpose. In- 

 deed that belief has not entirely i)assed away. 

 Since beginning this paper the author, in order 

 to demonstrate the truth of the matter, 

 inaugurated a series of experiments. Select- 

 ing from the I\Iuseum collection a dozen or 

 more representative specimens, he attached 

 to each an arrow shaft, smooth, straight, with- 

 out feathering, and the same size throughout. 

 Eepairing with these to the top of the tower 

 of the Smithsonian building, he began by 

 letting them drop straight to the ground, 

 carried only with their own gravity, and next 

 launching them in the air in every direction. 

 He found a universal rotation. He pushed 

 his experiments further by arranging these 

 specin)ens in a sort of clamp of wire, the 

 ends of which embraced the ends of the arrow- 

 points, care being taken to put the point of 

 contact as near the center of gravity as i)os- 

 sible. Thus held, the suspended or clamped 

 implement was free to rotate longitudinally in 

 either direction on the application of the 

 slightest force. This machine was then used 

 by j)ushing it with its clamped arrowpoint 

 rapidly through the water in a large tub, and 

 it was discovered that the resistance of the 

 water produced a rotary motion of the imple- 

 ment. A more conclusive test was made at a 

 machine shop where the arrowpoint, hung as 

 aforesaid, was presented point foremost to the 

 pipe of air from the driving fan, when the 

 current immediately set it revolving. When 

 the force of the current was increased, it in- 

 creased the rapidity of the rotary movement. 

 When the arrowpoint was turned about so 

 as to present its base to the current of air, no 



rotary motion was produced. 

 These experiments were extended and continued to include any and 



every kind of bevel-edged arrow])oint and spearhead, always with the 



same result. It was obvious that the arrowpoint at rest ijreseuted to 



Fig. 180. 



PECULIAR FORM OF ARROWPOINT, 



WITH BEVELED EDGES. 



Elkton, Giles County, Tenne.ssee. 

 Division IV, Class A. 



Kalur.il size. 



