PLATE 17. 



Enlarging and reducing camera, showing method of mounting the apparatus. 



On the table at the left is a Petri-dish poured plate held in place by two rubber bands and ready for photographing. On the table at the right is a specia 

 camera-back used in making lantern slides. This allows the ground glass to be railed or lowered, pushed to right or left, or rotated at will 



