BIRDS IN RELATION TO AGRICULTURE 179 



is nailed on, to keep the nest dry. The top is hinged to the 

 back-board, and when in use is fastened down by means 

 of a screw, which permits the Hd to be opened for the pur- 







,^ 5'.. 



-t 



i 



^ 



s-.^— 



Flo. IV.— CONSTRUCTIONAL DETAILS OF A BIRD-HOUSE DESIGNED 

 BY THE AUTHOR TO BE MADE FROM SLAB WOOD, USUALLY A 

 WASTE PRODUCT FROM SAWMILLS 



The size given is siiitable for a bluebird, but the dimensions may be changed in 

 accordance with the table on page 180 



1. Cover 3. Back view 



2. Front of box 4. Section of box 



5. Complete bouse 



pose of cleaning out the old nests. By so utilizing waste 

 hmiber these boxes were made very cheaply at the sawmill. 

 A boy could readily make similar boxes. Fig. IV (5) shows 

 the box complete. In the first year (1908) 60 boxes were 

 distributed, and 31 per cent were occupied. The number 



