Page:Popular Mechanics 1928 01.pdf/156

 weeks did he have access to a photographic dark room. Obviously, carrying 150 loaded holders would have been out of the question (two negatives in each holder). Moreover, the use of roll film would have been impractical. Glass plates would have been impossible because of the weight and bulk, and vulnerability; therefore, the use of cut film was the only practical solution. There, again, the problem of loading and unloading the holders in the field, had to be solved.

I therefore went to work in my home workshop to develop some sort of a device that would permit the loading and unloading of cut film in the field, independent of dark rooms, or without being compelled to wait for night to do the job. After much experimenting and various trials and errors, the loading box shown in the accompanying illustrations was made up. It weighs but 8 lb., is easily portable, and turns the trick to perfection. Its use enabled me to produce 300 perfect negatives, with only six holders. I was able to load and unload these holders by daylight anywhere in the field, and to mail the exposed negatives home for development, as fast as they were put through the camera. This obviated the necessity for developing negatives under the unsatisfactory conditions one faces in the field, or taking a chance with some doubtful local laboratory technicians.



The box is made of basswood, carefully mortised, finished in cherry on the outside, and painted black inside. It is 22 in. long, 7 in. deep. and 18 in. wide. This gives ample space for handling the 5 by 7-in. cut films with which I was working. For handling larger negatives it would be easy to increase the size of the box. The box has a carrying handle like a suitcase, so it can be transported with no more difficulty. It is also provided with means for handling for handling panchromatic negatives, which must be loaded or unloaded in total darkness. I used more than 100 panchromatic negatives, loading and unloading them within the box, and did not have a failure with one.

Two square holes are cut in one side of the box, and fitted with hinged covers. To the inside of the holes are tacked and glued cloth armlets, made of heavy, light-tight black sateen and fitted with elastic wrist bands. A rectangular opening is cut in the top of the box and rabbeted to hold a red glass, and a lid is hinged to fit over the glass. When in use, a package of unexposed cut film is placed inside the box, on one side, and an empty cardboard box on the other. The film holder is placed in the center between the armlets, the lid closed, and the hands thrust through the armlets. The exposed film is taken from the holder and transferred to the empty box, then the holder is reloaded from the fresh package. The operator can easily see what he is doing through the ruby glass in the top. 