6o Wild Birds 



should be parallel with the nesting bough (when there is one), 

 and the long axis of the latter should be parallel with the sun's 

 course. The tent is so placed that the nest is in direct line, not 

 with the middle of the tent, but with the window to one side. 

 When the observer stands within, facing the nest, the window 

 lies to his left, at one side of the vertical pole, and either just 

 over the cross-piece or somewhere below it, depending on the 

 height of the nest from the ground. The tent will not over- 

 shadow the nesting bough when once set in proper position. 



If the focal length of the lens be 6 inches, and the nest that 

 of a Cedar Waxwing, which is mounted at the height of four 

 feet, and the tent be so placed that the front of the lens is 

 twenty-eight inches from the rim of the nest, we shall get a 

 picture with adequate setting on a 4 x 5 plate, like many shown 

 in the engravings. With lenses of longer focus, which it is 

 advisable to use if possible, it is not necessary to approach so 

 near. 



When the position has been determined, the tent-poles are 

 set firmly into the ground, the ridge-pole adjusted and the tent- 

 cloth thrown over it. It saves time to lay one end of the peak 

 in position and draw the other over to its proper place. The 

 cross-pieces are then lowered from the inside and the guys 

 loosely set. A flap about six inches square is then cut with 

 scissors in the front of the tent, to the left of the pole opposite 

 the nest, which can be viewed 'through the opening. Should 

 the position subsequently prove to be wrong, the poles may be 

 raised both together and reset. When everything is right the 

 guys are tightened, and the free edges fixed to the ground with 

 wire pins, which will hold the walls taut and prevent excessive 

 flapping when there is wind. It is often convenient to have 

 the flap at the front on the operator's left so that one leg of the 

 tripod may project through it. 



The proper adjustment of the camera follows, the nest being 

 the object focused until the old birds appear. I have found it 

 advantageous to pin the focusing cloth firmly around the 

 camera so that it is always in position for use, and to stretch a 

 piece of green denim on the side of the camera next the observer, 



