BIRD-PHOTOGRAPHY 157 



image ; for this a long draw of bellows and a long 

 focus lens are needed. They are the only absolute 

 requisites. Other improvements which can be se- 

 cured without much additional expense are the 

 reversible back and the swing back, the first of 

 which will come into frequent use and the second 

 into occasional use in photographing nests ; but 

 they are not essential. 



Another device which the author has found 

 such a constant convenience and time-saver as to 

 be almost indispensable is a ball-and-socket at- 

 tachment to go on the tripod to which the camera 

 is to be attached. This allows the camera to be 

 pointed almost instantly in any direction, and 

 frequently when quick work is demanded may 

 be the means of securing a picture which might 

 otherwise be lost, and in all cases it is a wonder- 

 ful convenience. 



Incidentals. — Another device, which under 

 certain conditions may be so essential that with- 

 out it no photographs can be secured, is a steel 

 rod about a foot long and three eighths of an 

 inch in diameter. At one end it tapers and is 

 provided with threads so that it can be screwed 

 into any tree or post. Near the other end is a 

 plate three inches in diameter, with a hole in the 

 centre, allowing the camera and ball-and-socket 



