struments, such us the multispectral viewers, spectral 
densitometrs etc. Let us mention for example an instru- 
mental set of the firm International Imaging Systems 
and Spatial Data System Ine. The enumeration of the equi- 
pment is far from being complete and the listeners will 
kindly forgive me having presented only a few of the na- 
mes chosen by chance. Gaining the instruments mentioned 
comes across big financial difficulties at the majority 
of schools. Those of us, who have the honour to be peda- 
gogues, know well that the pochet of the authorities res- 
ponsible is not always open for us. 
As necessary aids the series of suitable aerial pho- 
tographs are to be taken, as well. I am sorry that I 
don't remember the name of the author, who uttered the 
piece of knowledge, which I suppose to be the basic one. 
Education in Photointerpretation and I think that the 
same concerns the Remote Sensing as well, depends on the 
number of the aerial and in the other case of satellite 
images which the student.had the possibility to see. The 
more pictures imagining various objects in the different 
parts of the world à student has the possibility to eva- 
luate, the better view on the perticular phenomena on 
the picture he is able to get. 
Getting a satisfactory number of suitable photographs 
means for many universities the same problems as to get 
expensive equipment. There are practically no suitable 
sets of aerial photographs having a sufficient large va- 
riety, that means the photos of various objects and coun- 
tries. If the following information is correct as yet,it 
could be possible to order the acrial photographs for 
example "Air Photo Pack" produced by the firm C.F.Casella 
with the cooperation of the British Geographical Associa- 
tion, ITC - Hothmer stereo slide collection, IGN -l'exa- 
men stéréoscopique des photographies aériennes. But the 
series have useally rather a close view and in many ca- 
ses it can be said that they are somewhat expensive. In 
getting the pictures the problems of keeping them secret 
play also a considerable part. 5