In the United States there are to-day probably about ten thousand professional 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 picture 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 Lear.” Here is another study, “A Game of Sixty six.” Those are all silver prints, made with chloride of silver, using glass negatives and producing the positives by having the chloride of silver in albumen. The best vehicle to-day for making positive prints is albumen with chloride of silver. It is found that if you take a mixture of gelatine and bichromate of potassium, and put into the mixture some pigment and expose it under a negative where the light acts, the gelatine is made insoluble and holds the pigment, and where the light does not act the gelatine is still soluble and can be washed away. Here is such a picture and it is very interesting--“In Camp.” The shadows in that picture are on the white paper underneath. Here are a couple of pictures of silver, two Bavarian pictures. This one, of a little girl, is by Einlander of Cologne, instantaneously taken without a head-rest, which is a very difficult piece of work. This is the same idea, instantaneously taken. Here are two pictures very interesting, which were in the exhibition at Chicago. They are pictures in platinum, showing that we are not confined to simply silver salts. We have here in this last picture one of the chlorides of platinum, the platine chloride. It cannot be spoiled in any way. The picture is good as long as the paper is good. Here is an example of a yacht picture. It is the English yacht Iris. It is a fine picture. The yacht is travelling very fast. Here is a picture on the East River, made by Dr. Habershaw, showing the work of amateurs in this line.