(45) 
Fig. 14 Pako printer with inflated rubber platen as introduced in the R.C.A.F. in 1929 
system. The 5" x 5" negatives from the Eagle V cameras are enlarged to 9" 
x 9" on precision fixed focus enlargers which use the Western Union concentrated 
arc as a source in a condenser illuminating system. The paper used is double 
weight bromide. Prints are exposed and dodged on the basis of experience. 
Prints are not ferrotyped. 
England 
Most printing in England is done on a bromide emulsion. Apart from this 
details of the printing procedures vary considerably. The Directorate of Colonial 
Surveys uses the following three methods. Prints are made on waterproof 
bromide paper with a hand-operated contact printer, hand processed, and dried 
without ferrotyping. Exposure is determined by experience. The printer uses 
a baize covered pressure pad. Contact has been checked by examining definition. 
There is no special control of ambient conditions. Prints are also made on normal 
weight paper using the Multiprinter, when it is not intended that they be used 
for measurement. Exposure is determined by an estimate supplemented by a 
photoelectric cell reading. In the Multiprinter the paper is processed in a con 
tinuous roll. It is not ferrotyped. A reduction printer is also used to make 
prints on a lantern slide emulsion. Some distortions are known to occur in this 
method although the cause of them has not been established. The temperature 
rise of the negative is about 10°F.