An attempt has been made to apply a time regulator to the pneumatic exposer that shall keep the lens uncovered for a period of time at the will of the operator, which shall be regulated by an index pointing at a figure representing a definite period of time. By turning the index to any figure, from 1 to 20 or more, representing seconds, the shutter is held open for that time, and then closes automatically. This shutter is opened, in the first instance, by pressure upon a bulb, p125 in the same manner as any of the pneumatic devices. We may enumerate, among the various shutters, those giving the most satisfaction in use,
CADETT'S PATENT PNEUMATIC PHOTOGRAPHIC SHUTTER.
It has often been remarked by eminent photographers that the arrangement is a most useful one which enables persons to be photographed without being aware of it. The efforts in this direction necessitated the operator being close to the camera; here we have an instrument which permits him to be at any part of the studio he pleases.
Many have experienced the difficulty of taking children's portraits with the proper amount of profile; with the above device all difficulty vanishes—the operator may be by the side of the child and attract its attention to any direction, and he has the means of exposing and capping the lens with far greater rapidity than with the usual method.
Directions.—After the day's work is done the rubber tubing should be taken off the instrument; this will prevent a partial vacuum in the bellows and tube, which would otherwise ultimately occur. These instruments are now constructed for application either inside or p126 outside the camera. Its use is very simple—squeeze the ball end of the tube and the shutter opens.
This instrument no sooner made its appearance than Yankee ingenuity set to work to improve on it, or at least to produce something similar that might not infringe on the patent.
The first effort was to bring electricity into use to move a shutter inside the camera box, and a very good device was perfected and sold to numbers who were convinced of the usefulness of the idea, but were unwilling to pay the price demanded for the English instrument. This electrical apparatus, however, soon played out, and few operators had the time or knowledge necessary to keep the battery in order; and in many instances after the sittings had been made it was found, on attempting to develop the plate, that no exposure had taken place, hence these electrical shutters were soon relegated to the limbo of played-out photographic apparatus, of which every gallery of any standing has one. p127
