THE ALUMNI JOURNAL. 



39 



careful that the light does not get to 

 them. The consequence is that the 

 plate holders are made with extreme 

 care. 



The result of this gelatine-bromide of 

 silver process is this : that we can have 

 plates in packages. We can put these 

 emulsion plates and carry them off where 

 we please, and, what is still more import- 

 ant we can put the emulsion upon very 

 thin material, and I have here (exhibit- 

 ing them)thin sheets of celluloid upon 

 which this emulsion has been spread and 

 pictures taken. That is not all, either; 

 they can make it still thinner (producing 

 small eamera) they can put it on a roll 

 and in this camera is one of those rolls, 

 and in that box I can take a hundred 

 pictures without reloading the instru- 

 ment. The way it is done, I, when I 

 want to produce a new surface, simply 

 wind the old one off with this winding 

 machine. There is an opening at the 

 front of the camera. Press just below 

 this, so, and you have the picture. Now 

 just wind the film off and you are 

 ready for the next picture. Now 

 pull it again, and this is so easy that some 

 manufacturers say : "You simply push 

 the button and we do the rest for you." 

 That is nonsense, they don't do the 

 "rest" for you. A friend of mine took 

 one of these to Europe, and with it a 

 dozen rolls of film, all of which he used. 

 When he returned he sent them to the 

 manufacturers and I think he got about 

 twelve pictures back. Not every time 

 you press the button is a good picture 

 produced. You have to know a little bit 

 about the science and use a little judg- 

 ment. 



Such is the state of photography to- 

 day that this material can be spread 

 upon any kind of transparent surface. In 

 the case of plate, they are put in holders 

 like this, generally only two on each 

 side, and slipped into this frame in a 



dark room, in which no light can be 

 used except one emitted through a deep 

 red chimney. (The professor here exhib- 

 ited such a chimney.) Then, the mate- 

 rial that is used for developing these 

 pictures is somewhat different from the 

 old method. We use organic compounds, 

 alkaline solutions, and organic matters 

 capable of taking up oxygen. These 

 organic materials, in conjunction with 

 some alkali, are capable of taking up 

 oxygen. They produce a disozygenizing 

 action. After dipping, that gives you 

 the negative. 



The prints are made in a variety of 

 ways. The facility with which these 

 apparati can be used has led to an enor- 

 mous variety. You can have an appa- 

 ratus something like that, or something 

 like this, which is smaller. 



In the United States there are to-day 

 probably about ten thousand profes- 

 sional photographers and thirty or forty 

 thousand amateurs, who usually do 

 nothing but spoil plates. To give you 

 an idea of some of the work done, not 

 altogether by professionals, I have picked 

 out from the number of pictures I have a 

 few samples of the work. Here is a pic- 

 ture of a cattle ranch in Colorado. I 

 have one a little larger of a horse race, 

 but this is about as large as they can 

 be made. That will give you an idea of 

 the instantaneous effect. The distance 

 between the foot and the top of the 

 mountains is about twelve miles, so that 

 you can get an idea of the capacity of 

 the camera, of the sensitiveness of these 

 compounds. Here is a Mexican picture 

 which shows the great beauties of the 

 Mexican flora — the cacti. Here is a 

 study "King Lear" made by Buffler, 

 the photographer. That is about as 

 large as you can get. It is a pretty large 

 plate to handle. Then there is another 

 study "The Five O'clock Tea" some 

 ladies at tea, by the same man as " King 



