The HOLOSTIGMAT LENS 



for 

 Instantaneous 

 Photography 



IS THE BEST 



m 



Dull 



Weather. 



Gives perfect definition over the whole plate at full aperture, and 

 yields crisp negatives entirely free from haze and false reflections. 



These conditions can only be obtained in Lenses which consist of 

 Cemented components. 



The Holostigmat is made with cemented components, 



LENS LIST SENT POST FREE. 



W. WATSON & SONS, LTD., 313. High Holborn, London . 



R. H. PORTER, 



Natural History Bookseller and Publisher. 



SPECIALIST IN BIRD BOOKS. 



MONOGRAPHS— clean, sound, and perfect condition. 



LORIIDi^, or Brush-tongued Parrots, with 61 hand- £ s. d. 



coloured plates and 4 maps 4 14 6 



MEROPIDi^, or Bee-eaters. with 34 hand-coloured 



plates 4 4 



CORACIIDi^, or Rollers, with 27 hand-coloured 



plates ... ... ... ... ... 4 4 



HIRUNDINIDiC, or Swallows. 2 vols, with about 



1 30 hand-coloured maps and plates ... 6 10 



Also Kingfishers, Sunbirds, Pittidae, Barbets, Birds of Paradise, etc. 



Prices on Application. 



BOOKBINDING BY OUR OWN WORKMEN. 



7 PRINCES STREET, CAVENDISH SQUARE, LONDON, W. 



