28 



Pictures of Bird Life 



JB 



S, Spring ; S', Screw, — both connected with insulated wires to battery 

 and electro-magnet of shutter. The slightest touch on silk causes S to 

 touch 5', which completes the electric circuit, and causes the shutter to 

 open and shut, wherebj' the plate is exposed. 



The camera, it is needless to say. niiist be most carefully 

 concealed ; it is, in fact, upon the thorouoli concealment that 

 eventual success depends, for very many birds will not ap})roach 

 their nest if their suspicions are too much aroused, but will 

 desert their eggs alto^-ether, and some birds will even desert 

 their young ones. I lun e known 'i'urtle-doAes to do so ; but 

 this is, I imagine, a very extreme case. 



When a nest is, like a Lapwing s, placed in the middle 

 of a field on the bare ground, it is not an easy task to so 

 diso-uise the camera as not to alarm tlie ])arent birds. It is 

 impossible, of course, to so conceal it as to leave nothing sus- 

 picious ; there must be some lump which did not exist before, 

 however you may attempt to do away witli it. And it is just 

 here that human ingenuity comes into play. It is. for instance, 

 a capital plan to gradually accustom the birds to this necessary 

 lump before they begin to sit, l)y piling up two or three clods 

 of earth some yards away, and gradually decreasing the dis- 

 tance, so that thev become familiarised with its appearance. 



