ON PHOTOGEAPHS OF GEOLOGICAL INTEREST. 323 



affected by denudation, or where marked physiographical changes are in operation ; 

 raised beaches ; old sea cliffs and other conspicuous instances of marine erosion ; 

 characteristic river-valleys or escarpments, and the like ; glacial phenomena, such as 

 roches montonnces, moraines, drums and kames, or any natural views of geological 

 interest. Photographs of microscopical sections, and typical hand-specimens of rocks 

 are also admissible. 



Your Committee held a meeting at Leeds and discussed several details 

 of the work, which has been principally carried out through the medium 

 of correspondence. 



Regarding the question of the disposal of the photographs, it was 

 decided to defer any recommendation on the subject until the collection 

 was in a more complete form. 



Reference was made in the last report to a proposed publication of a 

 series of the best photographs received by the Committee, reproduced 

 by a permanent process. The suggestion has received the careful 

 consideration of the Committee. It was decided, however, to defer the 

 subject until the next meeting of the Association, when, if any arrange- 

 ments with a publisher could be made, the Committee would probably be 

 in a position to select a series of approved photographs for the purpose 

 of authorising their reproduction, with the consent of the owners of the 

 negatives. 



A desire having been widely expressed for facilities by which lantern slides 

 of the geological photographs included in the list issued could be procured, the 

 Secretary was instructed to endeavour to make arrangements to effect this 

 object. Owing to the fact of the negatives not being in the possession of 

 the Committee, the privilege of supplying lantern slides remaias in the hands 

 of the various photographers. In the case of professional photographers, 

 there is usually no difficulty in supplying these to teachers and others 

 who may require them. Negatives taken by private persons are not un- 

 frequently handed over to a professional photographer, who has authority 

 to supply slides to the public. Applications for slides should, therefore, 

 as in the case of ordinary prints, be made to the photographer direct, whose 

 address is, whenever known, printed at the head of each local list, or else 

 to the local society under whose auspices the photographs were taken. 

 In order to meet the convenience of amateurs who do not make their own 

 slides, but who would be willing to lend their negatives for the purpose 

 of having slides made, the Secretary has effected an arrangement with an 

 experienced photographer, who will landertake to supply lantern slides, at 

 a tixed price, from negatives with which he may be temporarily entrusted. 

 It is understood that this arrangement only applies to those cases in which 

 the owner of the negative does not desire to supply them himself. Future 

 lists will contain the needful particulars as to obtaining lantern slides ; in 

 the meantime persons desiring to avail themselves of the arrangement 

 above mentioned may communicate with the Secretary. 



Your Committee are pleased to observe the spread of geological photo- 

 graphic schemes in countries abroad. The Societe Geologique de Belgique 

 have, on the recommendation of M. G. Dewalque, adopted a form similar 

 to that of form 'A' issued by your Committee for recording the details and 

 registering the numbers of photographs contributed to their own collec- 

 tion, and a copy of this schedule is inserted in the ' Bulletin ' of the Society 

 for July, 1890. 



The Geological Society of America have also appointed a Committee 

 on Photographs, which has already made good progress, nearly 300 



Y 2 



