Arizona republican., 1919-03-24

partment. This camera, which took an 1S-cmX24-cm picture, had a focal length of twenty inches, and held a roll of film on which 100 successive eX- posureS could be made, weighed only 5 pounds. Its most novel feature was the vacuum back" consisting of perforated sheet which extended across the top of the chamber and over the face of which the film passed. A slight air suction. produced by d Nentur1 tube placed where it would catch the rush of air past the plane, served to hold the film absolutely flat-for the slightest curvature of it's surface would play havoc with the perspective of d picture taken from a height, say, of 19,00o feet. This ingenious camera was driven by an electric motor which changed the film automatically set the shutter the observer having only to set the machinery going to regulate it's | speed according to the rate of travel of the airplane in order to obtain a se- ries of pictures forming a continuous 1 photograph of the territory over which the machine was passing.
 Another picturesque phase of earial | photography of which the public has 1 heretofore been permitted to know next | to nothing was the so called gun cam | era the invention of Thornton Pick ard of Altringham, England. This | camera, which Was designed for the purpose of training aerial gunners, | initiated as closely as possible Marlin aircraft machine gun, and. in order to make a picture. it was necessary for | the operator to go through the same movements as in firing Marlin gun. | The picture was made through a cir I sight on the fixed machine gun. so, if the film. upon being developed, showed that the gunner had scored q Init" with the camera, he would have been equally successful with an actual | machine gun. The gun cameras as de- | veloped in the United States were of | two kinds one, using a regular | Brownie film, took one picture each time the trigger was pulled; the other
 which was virtually motion picture | camera so constructed as to exactly | replace the magazine on Lewis gun
 gave 'burstc of exposure with a rapidity equallying that of a machine gun firing a burst of shots, and was used for training aviators in the han ding of their flexibly mounting Lewis
 guns. The resulting film, or bromide print. consisted of a string of sil
 houettes of the supposed enemy plane
 each with an image of the sights l superimposed to show where the gun
 Wa sheld, with reference to the target
 at the instant the picture was taken. l. The enormous numbers of pictures
 taken from the skies necesSitated ]
 corresponding development and manu-
 facture of travelling dark rooms, [;
 complete units of these machines be-
 ing built and shipped overseas. These
 consisted of mobile photo laboratories
 having all the equipment necessary fol
 the rapid production of prints in the
 field for, when important operation:
 are in progress. it is imperative that
 the aero photographs reach the intel
 ligence section of the staff at the ear
 Hest possible moment after they art
 taken The dark rooms, which were
 mounted on trucks, were equipped witt
 apparatus for generating the curren
 used in the lamps and enlargers, While
 the trailers were fitted with skins
 tanks. enlarging cameras, and othel
 necessary photogra phic apparatus. Th'
 fact should not be overlooked. more 1 over, that provision had to be made fo
 training the vast and for the most par
 inexperienced personnel of the photo
 graphic sections in the countless new
 and peculiar phases of aerial photog
 raphy. for it is a far, far cry from tax
 ing family groups in city studio t'
 taking pictures of German field gum | from an airplane in the skieS-par
 ticulariy if those guns are shooting q ! yOu