586 ANNTJAL REPORT SMITHSONIAN INSTITUTION, 1962 



was that of selection, through measurements and tests, from a large 

 number. 



Another point of importance in accurate shooting at long distances, 

 such as 100 yards in the York Kound, is that the drag on the arrow 

 must be alike for all. The principal cause of variation in drag has 

 been in the vanes made of turkey feathers, which are easily dis- 

 arranged or damaged by mechanical impact, and changed in texture 

 and uniformity when wet. In the new designs, plastic vanes are used, 

 with the result that greater uniformity is achieved with smaller ef- 

 fort. Some experimenters and manufacturers have used four or six 

 vanes in place of the usual three. The only advantage is that for 

 the same area of stabilizing surface, the larger number may be made 

 somewhat narrower, and this may have value in preventing contact 

 of the vanes with the bow when the arrow is loosed. 



The drastic changes made in bows and arrows during the three 

 decades past have produced emotional reactions among the older arch- 

 ers to whom the legend of Eobin Hood was sacrosanct, and who were 

 unable to tolerate innovation. They lived in the old English tradi- 

 tion with the longbow and the arrows made of "old deal." They 

 ridiculed the research and development which pointed the way to 

 better shooting and higher scores. Clearly they were entitled to hold 

 affectionately to the Robin Hood image of archery. However, their 

 predictions about the decline of archery, caused by the newfangled 

 gear, failed of fulfillment. The number of archers has moved from 

 the thousands into the millions. In large part this has come about 

 by leaving tradition behind. The new bows and arrows have added 

 immeasurably to the potential enjoyment of the sport. 



A brief compilation of some of the technical considerations involved 

 in the advancement of the art will, I hope, interest many readers, 

 for it helps in following the rationale of the research and development 

 which have been described. 



The force-clraiu relation. — The most obvious characteristic of any 

 bow is the relation between the force and the displacement of the 

 nocking point of the arrow on the string. In graphic form, the 

 relation is expressed as the force-draw curve. It shows the force 

 exerted by the bow on the arrow at any point of the path in which 

 it experiences acceleration. 



In figure 8 are shown force-draw curves of bows of the several 

 kinds which are under discussion in this report. These are adjusted to 

 the same maximum force of draw at the same length of draw. 



The significance of the force-draw curve in these studies is the fact 

 that from it one obtains the energy in the drawn bow. The measure 

 of the energy is the area enclosed by the graph, the X-axis at 

 zero force and the ordinate at maximum force. The force-draw 



