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Cecil Shaw, Esq., M.A., M.D., read a Paper on 

 MODERN PHOTOGRAPHY. 



Dr. Shaw first dealt generally with the past of the Photogra- 

 phic art, and briefly laid down the chemical conditions which 

 render photography possible. He explained the process by 

 which the "dry plate" is produced, and the composition which 

 is used in preparing it. He dealt chiefly with three requisites 

 of photography, viz. : — Speed, quality of work produced, and 

 portability of apparatus. Generally, he gave a detailed descrip- 

 tion of the manner in which an ordinary photograph is pro- 

 duced. Dr. Shaw then proceeded to describe some varieties 

 and elaborations of the photographic process, beginning with 

 negative making ; and proceeded to consider the printing of 

 copies. Few people, he pointed out, know what marvels are 

 now performed in the way of quick photography due to modern 

 plates ; for, of the other two factors which determine the length 

 of exposure, namely, the brightness of the light, and the form 

 of the lens, one is unchanged, and the other not greatly altered. 

 For instance, the flight of cannon balls and rifle bullets is now 

 photographed, not as a curiosity, but as a scientific method of 

 studying the art of war. He said he was indebted to Mr. 

 Francis Meldon, of Dublin, for some splendid samples of instan- 

 taneous photography, and these were all the more interesting 

 to a Belfast audience as the mechanism used to open and shut 

 the lens was the invention of Mr. Thomas Caldwell, of Belfast. 

 Having explained the nature of the instantaneous process and 

 the requisite amount of exposure, he pointed out that with 

 Mr. Caldwell's shutter any desired exposure can be given, from 

 five seconds down to one-three-hundredth of a second. Pho- 

 tographs of the sun have, he believed, been taken in the one- 

 thirty-thousandth of a second. He also explained and illustrated 

 other forms of shutters for the camera. At this stage a number 

 of illustrations were projected upon the screen, showing the 

 results attained by different methods. The lecturer went on to 

 deal with, and give specimens of, detective and isochromatic 



