68 METHODS OF ATTRACTING BIRDS 



A swinging cover was screwed just above the en- 

 trance, and a long string attached to this so that 

 it could be pulled down and made to cover the 

 hole. The house was watched until a sparrow was 

 seen to enter, which was trapped inside. It was 

 kept overnight and then the cover was removed ; 

 but the bird seemed in no hurry to leave the box, 

 and it was only after renewed pounding on the 

 box that she was driven out. Investigation showed 

 that she was incubating her eggs, and that the 

 trap-door merely forced her to do what she would 

 naturally have done anyway. 



Sioinging Houses. The device of a swinging 

 house seemed at first to promise satisfactory re- 

 sults, because the principle had worked perfectly 

 during a winter's experience while feeding birds 

 on a swinging lunch-counter. In order to try this 

 plan on a large scale the author visited the 

 schools situated in the more favorable districts 

 of the city where he lived, and explained the 

 matter to the children and asked their coopera- 

 tion. Some bird-cage springs were furnished to 

 the children; but as the supply was soon ex- 

 hausted, the children were told simply to suspend 

 their houses by wire. As a little incentive, a prize 

 was offered for the best account of experiences 

 with the bird-houses. The children responded 



