(51) 
Sweden 
Swedish Cea bromide paper is used. Contact prints are made in a Kodak 
30 x 30 cm printer, the platten of which is lined with sponge rubber and felt. 
Processing is manual. For making diapositive plates the Zeiss wide angle reduc 
tion printer is used. Ambient conditions of 20°C and 40% relative humidity 
are normal. Prints are usually not ferrotyped. 
Switzerland 
Prints for reflected light viewing are made on DuPont velour black paper 
and on Tellko Correctostat. The paper shows 0-7 to 1 % shrinkage. The Correc- 
tostat is stable to 1 promille (0-1%). Diapositives are made on a Gaevert 
emulsion on glass and on a Typon Swiss emulsion on film. The glass is stable 
to 0-1 promille (0-01%), the film to 1-2 promille (0-12%). The contact 
printer used in all cases has parallel light from a small source and uses a suction 
frame. Exposure is determined visually or by sensitometric control. Ambient 
conditions are 18 to 20°C and 40 to 80% relative humidity. Paper prints are 
not ferrotyped. 
United States of America 
In general chloride papers are used for contact printing, and bromide 
papers for projection printing, with some use of variable contrast papers for 
both purposes. Diapositives are nuide on glass plates. Paper surfaces used are 
generally semi-matte such as Eastman Grade E although the U.S.A.F. also use 
glossy paper. Some use is made of waterproof papers such as Grant’s Air Map 
Special. The Coast and Geodetic Survey also cement 36" x 36" commercial 
bromide enlarging papers onto 0-040 inch thick aluminum sheets with gelatin to 
provide a dimensionally stable base for stereo-topographic mapping with the 9 
lens photographs. Contact printers used are the Fairchild Incandescent, the A-ll, 
the A-14, and special vacuum frames. Projection printers are the Bausch & 
Lomb reduction printer, the Eastman projection printer No. 2, the Saltzmann 
enlarger, and for the 9 lens camera a special 9 lens transforming printer. Most 
of the contact printers use inflated pneumatic pressure pads. A check with a 
negative halftone screen has shown contact to be good. Ambient conditions in 
printing are controlled to 70°F and 50% relative humidity by the U.S.A.F. 
Elsewhere higher temperatures and various humidities are encountered. I he 
U.S.A.F. report temperature rises of 40°F above ambient in contact printers and 
60° above ambient in enlargers. Processing procedures are generally manual and 
follow manufacturer’s recommendations. The U.S.A.F. use sensitometric con 
trol. Prints are not ferrotyped except for the glossy prints made by the U.S.A.h. 
VIII. NAVIGATION DEVICES 
Introduction 
Various type of radar aids are in use or in experimental stages. 
Australia 
A Williamson type of drift sight is used.