184 



THE ENGLISH SPARROW IN AMERICA. 



bird in connection with the movements of the nets, and to so control 

 the force of pulling in closing them as to cause the net to strike the 

 bird when the radius of the semicircle of either wiog is at a vertical 

 point. The irregularity of the flight of the Sparrow makes it difficult 

 to catch many at one time. 



Fig. i. 



Fig. ii. 



The mechanical operation of these nets is shown in Figs. I and IE. 

 Fig. I shows nets open, lying flat upon the ground. By pulling pull- 

 line (//) each net is caused to move upward and inward to the comple- 



