GVII-la (Sup.) 
GENERAL 
General Summary 
Reports included in the supplement show the same high 
general level of interest and activity in photographic inter 
pretation that was evidenced in the basic report. For ex 
ample, the Netherlands reporter states that in that country, 
approximately £,000 people per year, in such occupations as 
architecture, municipal planning, farming, fruit growing, 
and the like, are informed of the potential application of 
photographic inteipretation to their problems. Many of these 
become regular users of the results of photographic inter 
pretation. 
In Switzerland, the applications of photographic 
interpretation are somewhat limited, due to the country*s 
limited surface, and the availability of good, large 
scale topographic maps. Nevertheless, during the re 
porting period, photographic interpretation showed a 
marked and steady increase. The importance and the 
enormous value of the use of photographs are fully re 
cognized and the demand for photo material is contin 
uously growing. To satisfy these requirements, many 
photographs are taken and made available by the Swiss 
Government's Topographical and Cadastral Surveys. Due 
to the availability of these photographs, it is therefore 
only rarely that aerial photographs are specially taken 
for photographic inteipretation purposes. 
Research and Training 
At the Swiss Federal Institute of Technology summer 
and winter courses in photo interpretation are compulsory 
for advanced students of geology. They are open for 
students of geography and of various branches of civil 
engineering. As a supplement a special introductory 
course in photogrammetry is given annually by the pho- 
togrammetric division of said Institute. It is intended 
to further the training of geologic engineers, among 
others, and ultimately leads to the necessary acquaintance 
with second order precision plotting. Courses in photo 
inteipretation use lens and mirror-stereoscopes, parallax 
bars, an aero- sket chinas ter by Zeiss, a polarising twin 
projector and other instruments. This special introductory 
course uses second and first order precision plotting 
machines such as the Wild A6, A2, A£, and other similar 
equipment. 
The forestry and agricultural departments of the 
Federal Institute of Technology, Switzerland, use aerial