196 The Bluebird 
their enemies, of which the house wrens, and especially 
the English sparrows, are chief. However, owing to 
the continuous warfare waged against them by these 
pugnacious foes, the bluebirds are, year by year, 
becoming less numerous about our dwellings. 
In my bird note book I find a sketch of the blue- 
bird families that have, for several years in succession, 
occupied my “‘bird-box.” This artificial home con- 
sisted of a hollow limb, about twenty inches long 
and eight in diameter, closed at top and bottom, and 
having an entrance for the birds on one side, while 
on another side was a door, through which the nest 
and its contents could be inspected. In the wall. 
opposite to the bird’s entrance a microphone was 
arranged, and a line joined it to a telephone re- 
ceiver in the house. This unique “bird-box”’ 
was 
located about twelve feet above the ground and made 
fast to the body of a tree that stood in the rear of the 
house. 
I did not expect to obtain results that could any 
more be turned into words than could the music of 
the veery or the murmuring of a mountain stream; 
but I wanted to hear the notes of the old birds and 
young, when undisturbed by man, and this was the 
only method known to me of accomplishing the de- 
sired end, 
