148 THE BIRDS OF NEW JERSEY. 



it being best to attract its attention while on the wing, as 

 well as to prevent it from discerning anything unusual. 

 The skillful operation of the nets in the main consists in 

 properly judging the flight of the 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 semi-circle of either wing is 

 at a vertical point . The irregularity of the flight of the 

 Sparrow makes it difficult to catch many at one time. 



"The mechanical operation of these nets is shown in 

 Figs. I and II. Fig. I shows net open, lying flat upon 

 the ground. By pulling (d) each net is caused to move 

 upward and inward to the completion of a half circle, one 

 net slightly overlapping the other when closed, as shown 

 in Fig. II. The four points of each net formed by the 

 two cheeks (f) and two heel pins (e) are on a straight 

 line. The nets are stretched tight over the tops of staffs 

 (b) which have socket attachment and work on wire in 

 check as a pivot or hinge. The tension on pull-line will 

 keep the nets straight and even, except when a strong 

 wind blows across them, in which case the arm or pull- 

 line is shortened or a pully (j) attached. 



u The nets should be made of linen material, about the 

 size of No. 35 gilling-thread, of a dark, dirty-green color, 

 the size of mesh being thirteen- sixteenths of an inch 

 from knot to knot or fifteen knots to a foot. A conven- 

 ient and serviceable size of net would be thirty feet long 

 by seven feet deep to use with four foot staffs. They 

 should be provided with an arming of heavier cord at the 

 top and bottom edges, to which the top line (c, Fig. I) 

 should be threaded at top, and to form a stout edging to 

 permit of pegging to the ground at bottom . 



"The top-line of the net should be a fine linen cord, 

 about one-eighth of an inch thick, provided at ends with 

 a small wooden clamp (i, Fig. I) similar to those used on 

 tents; and at the plaee where the net ends on the top line, 

 one or more loops or eyes should be spliced, to admit the 



