CORRESPONDINCr SOCIETIES. 63 



15. Of the photographs collected, the first c&iuplete set shall bo 

 deposited in some public institution (preferably the British INtuscum). 



Sets of survey photographs of local interest may also bo presented to 

 any local institutions (as free libraries and museums) which may be 

 willing and able to take proper care of them. 



16. If not fewer than — membera apply, a special sub-section or 

 sections may be formed, among whom a portfolio of survey prints (with 

 accompanying descriptive note-boobs) shall circulate. Such members 

 shall pay a small annual subscription to defray extra expenses. 



17. The inauguration and direction of photo-survey work in the 

 British Colonies may be one of the objects of the survey. 



18. Photography at sea, including meteorological phenomena, types of 

 vessels, of seimen, waves, icebergs, marine animals and plants, il-c, may 

 be one of the special subjects of Avhich records shall be obtained. 

 Photographs taken by British travellers in unexplored, wild, barren, or 

 savage regions of the earth, such as the Polar Regions, Central Africa, 

 &c., may also be included in the survey collections. 



19. An annual exhibition of the work of the survey may be held. 



20. The gift of negatives, as well as of prints, is solicited. 



21. Local photographic, literary, scientific, archaeological, and art 

 Societies may be afiiliated to the survey. Such Societies may aid in the 

 preparation of lists of objects and places for the work of the photo- 

 survey ; and by the help of their members as local guides and experts. 



22. The survey may appoint a professional photographer or photo- 

 graphers to do the work of printing, both for the survey and for individual 

 members. 



23. In any lists of the members of the survey which may be published 

 the number of prints contributed by each member shall be shown (in 

 brackets) after his name. 



24. A]}parati(s. — The following specification refer.s to a set of 

 apparatus which has been used for survey-work for several years past :^ 



(1) Ilalf-plate camera fitted with turn-table and bchind-lens shutter. 

 (2) Three double plate-holders, with pull-out aluminium slides. (3) Three- 

 fold wooden tripod. (4) Wide-angle lens (anastigmat), 5^ inches focus. 

 (5) Lens (anastigmat) for ordinary work, 8^ inches focus. (G) Changing- 

 bag and focussing-cloth combined. (7) Spirit-level. (8) Focussing-glass. 

 (9) Yellow screen (for orthochromatic plates). (10) Note-book and 

 exposure meter. (11) Stiff brown canvas carrying-case. (12) Ordnance 

 map of the district. The weight of such an outfit (loaded with six 

 glass plates) will be 14 lb. 



25. The ' half-plate ' is perhaps the smallest size which gives, in 

 itself, a useful print ; and yet it is not too big for the enlarging 

 apparatus. Enlargements to 23 by 17 inches are to be preferred for 

 wall-pictures. 



26. To get good enlargements we must use lenses capable of giving fine 

 definition, and the lenses recommended are most satisfactory in this respect. 



27. Plates are to be preferred to films, because of their possessing 

 a plane surface, which can be relied on to be in register with the focussing- 

 screen, and for their rigidity, although films possess the advantages of 

 lightness, non-breakability, and ease of storage, 



28. Each member shall be furnished with a ticket or book stating 

 that he is a member of the photo-survey, and giving l)ricf particulars of 



