Chlorhydrochinon developer, 261 Chromatism, lateral, 49, 54 City planning, use of aerial photography in, 396 Clock-work for driving cameras, 149, 155 Clouds, 224, 242 Collimator, 66 Color, coefficient or index of negative, 259 filters, _see_ filters photography, =385= sensitive plates, 15, 174, 233, 237 sensitiveness of film, 131 sensitizing, methods of, 235 Coma, =47=, 48 Communication, means of on plane, 296 Compass, 33, 173 reading recorded on film, 135, 171 Cone, camera lens, 42, 114 interchangeable, 108, 120 Construction operations, aerial photographic records of, 396 Contact, imperfect in printing, 279, 284 prints, 45, =279= Contacts, electric, on plane, 163 Contours by stereo aerial photography, 404 Control, distance, of camera, 110, 163 speed, of camera, 136, 144, 157 Controls, duplicate, 19, 25, 195, 209, 214 of plane, 21, 26 Convergence point, 337 Cord for adjusting shutter aperture, 82 Core rack development, 271 Contrast, in brightness on earth's surface, 221 in photographic emulsions, 15, 230, 236, 258 Counter, exposure, on magazine, 88 on release, 164 Covering power of lens, 44, =49=, 50, 58 Crabbing, 27, 308 Cradles, camera, 195 Cross wires, 23 insertion of camera through, 42, 210 Curtain, auxiliary shutter, 80, 84, 106 speed of travel of shutter, 74 uniformity of, 76, 82, 84, 86, 315 Cylinders, relation between vibration and number of, 185 Dark slides, double, 87, 99 Daylight, intensity of, 222 Definition, lens, 44 Density, of air, effect of on propeller, 154 of photographic image, 228 Developers, for plates and films, =257=, 260 for papers, =262= Developing machines, film, 133, =273= Ansco, 273 Brock, 274 Eastman, 274 G.E.M., 273 Development, core rack method of, 271 factor, 228 film, =272= methods of, =267=, 269 of prints, =286= speed of, 236, 267 tank, 270 time, 269 DH-4 plane, 210, 217, 296 photographic, 213 DH-9 plane, 296 Diaframs, to equalize illumination of plate, 78 lens, 48, 58 Dilution coefficient of developer, 258 Dirigibles, 15, 16, 413 Distortion, absent with between-the-lens shutter, 74 barrel, 51 due to camera tilting, 206, 286, 305, 315 in aerial maps, 317 lens, 39, 44, 51, 54, 56, 62 pin-cushion, 51 produced by film shrinkage, 237 produced by focal plane shutter, =74= produced by glass plate in front of film, 131 with wide angle lenses, 63 “Dodging” in printing, 279, 315 Doors in plane for camera to work through, 214 Drying of films, =267=, 276 of plates, 267, 275 of prints, =286= Earth, appearance of from plane, 30 Eastman apron film developing machine, 274 twin reel film developing machine, 274 Efficiency, propeller, 155 shutter, 70, =72=, 76 English aerial photographic practice, 45, 46, 283, 291, 340 EK filters, 241