27/40 This hole is so cut as to leave teeth resembling those of a large saw. This wheel is so arranged that it can be turned around, which should be done during the time of exposure in the camera. It must be placed between the camera and the sitter, and at such a distance from the camera as to allow such proportion of the body of the sitter be seen upon the ground-glass as is desired. It will be readily seen that by turning this wheel during the operation will produce the same result as the paper being moved in the other method. The teeth make the "blur." The side of the wheel towards the camera may be black, by which means the result will be a dark instead of a light border. |