270 BRITISH BIRDS. [vol. xiv. 



varying depth, on their faces, were also among them. Out 

 of a number of adult males two were very conspicuous by 

 reason of the splendid " tufts " they wore, the ends of which 

 touched their backs. 



As we watched, .four more Pochards arrived, a male and 

 three females, and were closely followed by an adult male 

 Tufted Duck accompanied by a smaller bird which we failed 

 to identify on the wing. They alighted on the ice, and from 

 there plunged into the water, where the strange bird began 

 to dive at once. It turned out to be an adult female Smew, 

 a somewhat rare visitor. It kept as far off shore as possible, 

 and was very wild and suspicious, offering no chance of photo- 

 graphy except at very long range. 



Photographic data may be of interest to some. A | -plate 

 refle.x camera was used on a stand, and its focal plane shutter 

 was set at 1/60 second. The lens was a Ross 17" telecentric, 

 and the aperture F 6.8. The best results were obtained on 

 super speed plates, speed 500-550 H. & D. The above- 

 mentioned shutter speed was found to be too long for birds 

 swimming quickly and moving directly across in front of the 

 camera, and in nearly every case the heads of the Coots were 

 blurred, owing to the rapid rate at which they were moved. 



