26 Pictures of Bird Life 



It would, however, liave been the lieiglit of rashness to rush 

 over to Holland to use an initried and untested apparatus, 

 espeeially one so delicate in manipulation. A whole week was 

 first spent at a I^apMing's nest not far from my house. Day 

 after day the trap Avas carefully set. and watched throuo-hout 

 the whole day from the shelter of a thick hedtie half-way across 

 tiie next field. Squatting in this prickly retreat, tlie birds could 

 be watched through the field-glass, and their actions and 

 behaviour noted. Each day one or other of the birds went on 

 to the eggs, and, duly setting the current in action, exposed the 

 plate ; l)ut it was not imtil the end of the week that a success- 

 ful photograph was obtained. First one slight alteration or 

 modification became necessary, and then another. The shutter 

 made for some time a slight noise — very slight it was. but quite 

 enough to cause the mother bird to spring up and completely 

 blur tlie photograph before the exposure was cojnpleted. Since 

 then some considerable improvements have been effected, and 

 to complete the circuit a bird now has only to touch an 

 invisible silk thread. This can be made to match the place — 

 green over grass, yellow oAcr sand, and so on — and can be 

 so delicately set that a 15utterfly, settling on it. would set the 

 battery at work. I Iuiac released the shutter by dropping a 

 piece of thin newspaper an inch square on to this thread. 

 Another difficulty had to be got over at the last moment. The 

 Lapwing sat on the release so long that the battery, kept in 

 action all tlie time, ran out. It then became necessary to work 

 out an automatic " cut off,"' which would prevent this waste 

 of battery action, howe\'er long the pressiu'e was maintained. 



