16 



j^reater extent than the last compact material. 

 If these results were remarkable when the pres- 

 sure only amounted to perhaps one hundred lbs. 

 per square inch and the denudation of gently 

 moving water for twenty-four hours, how much 

 greater must have been the i esults of a pressure of 

 millions of tons and a denudation extending over 

 tens of thousands of years, the results of which 



were shown in the contorted rocks of the river 

 gorges and in the mountain peaks 't 



The Chairman proposed a vote of thanks to 

 Captain McDakia for his lecture, which was 

 seconded by Councillor Wright Hunt, and carried 

 with enthusiasm. Captain McDakin briefly re- 

 turned thanks. 



SIXTH WINTER MEETING, 



TUESDAY, DECEMBER 18th, 1900. 



"TELEPHOTOGRAPHY."— BY MR. A. LANDER, Ph.C, F.S.M.C. 



The sixth winter meeting was held in the 

 Beaney Institute on December IS. Mr. S. 

 Horsley presided, and the attendance included: 

 Councillor VVhichcord, Mr. W. P. Mann. B.A,, 

 Miss C. Phillpotts, Miss K. Holmes, Miss Sworn, 

 Miss Holman, Miss Ellis. Mrs. Lander, Miss Mason, 

 Mr. C. Buckingham. Mr. W. Surry, Mr. F. C. 

 Snell, Mr. C. Hayward, Mr. J. Kennedy, Mr. J. T. 

 Smith, Rev. W. M. Rodwell, and others. 



A numbsr of interesting exhibits were placed on 

 the table: (1) four cards illustrating entomology, 

 botany and ornithology, etc.. by Messrs. Colman 

 and Co ; (_2) an instructive case showing the 

 manufacture of the lead pencil from the plumbago 

 to the finished article, both shown by Mr. J. T. 

 Smith ; (3) collection of British and foreign ferns 

 for the herbarium, presented by the President ; 

 (4) peculiar specimen of cyclamen from Bifrons, 

 with a regular pink line duwn one of the petals 

 shown by Mr. Sage ; and (.■>) additional micrO' 

 scopical slides, given by Bev. W. M, Rodwell 

 There were also two specimens of the ring (or 

 common grass) snake, shown by Mr. Fiddian. 



The President said a gentleman, named Mr. 

 Gerald L. Lithara, was compiling a work on 

 British snakes, and had written to the Society 

 askin? : "(a) Which is the most common snake in 

 Kent ? ; (6) What is the average length of the 

 adder in Kent 'f ; (c) What is the average length 

 of the ring snake r ; (tZ) Does the smooth snake 

 occur to your knowledge P " The questions could 

 beans wered by members of the Society, and he asked 

 any who were interested in Kentish snakes to send 

 the Secretary as much information as they could 

 on tho subject to forward to the gantleman in 

 question. 



Miss Pidduck and Mrs. Holman were elected new 

 members of the Society. 



Mr. Horsley said it would be remembered that 

 some little time ago when the Photographic 

 Society joined that Society, they had a smill 

 balance in hand, which, it was decided, should be 

 expended on books on photographic subjects to 

 be added to the Society's library. The balance 

 amounted to ^£3 123., and 17 boots had now been 



purchased with that sum, and were on the table 

 for the inspection of the members. 



The President then cjiUed on Mr. Lander, who 

 gave an illustrated lecture on Telephotography. 



Mr. Lander said it was very difficult to describe 

 the method and apparatus of Telephotography m 

 anything like popular language. Michael Faraday, 

 one of our best lecturers, once said that " Lectures 

 which really teach will never be popular; lectures 

 which are popular will never teacb." It will be 

 essential to say something about lenses and the 

 science of optics, and if some find this poition of 

 the lecture uninteresting, I trust they will bear 

 with me for the sake of the mmy amateur 

 photographers who should know mui^h about this 

 subject, to enable them to use their lenses to the 

 best advantage, and I trust that the numerous and 

 interesting lantern-slides that I shall throw upon 

 the screen will interest all, and wQI illustrate iu a 

 graphic manner the results to be obtained by this 

 comparatively new method of photography. 



Many an amateur photographer, having inad- 

 vertently left his lens at home, has before to-day 

 fixed his visiting card over the flange in his camera, 

 pierced a small hole in it with a pin. and by this 

 means secured a photograph that otherwise might 

 never have been his, or fallen to his lot again. 

 The pin-hole has some advantages over a lens, one 

 is that we can vary the size of our picture without 

 moving the camera. Suppose, when we see the 

 picture on the ground glass, we should like it to 

 be larger, we simply rack out the camera until 

 the picture is large enough to suit our fancy, or, 

 if we like it small, we rack the camera in until the 

 image is small enough. This is exactly what we 

 can do with more advantage in Telephotography. 

 The pinhole camera teaches us many things, and 

 gfives us a clear insight into the formation of 

 images of different sizes. I have tried to show 

 this in ¥iq. 1. The arrow A B represents the 

 object and P the pin-hole; the focussing screen, 

 with the inverted image, is represented at a 6, 

 al hi, and a2 b2 respectively. The squares, a, a/, 

 and a2, represent the outline of the picture, and 

 show how that the image ai, bein^ double the size 



