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•ès. 
OPENING OF THE VII INTERNATIONAL CONGRESS 
OF PHOTOGRAMMETRY 
O. S. Reading, 
President International Society of Photogrammetry. 
Thank you very much, Mr. Whitmore, for your cordial welcome to the 
VII International Congress of Photogrammetry. 
The American Society has indeed made excellent provisions for a most 
successful Congress. We shall do our best to benefit from them. 
Perhaps a few words about why and how we may all expect to benefit 
greatly from the Congress may help us to make the most of our opportunity. 
When Professor Schermerhorn visited the photogrammetric laboratories in 
Washington a few years ago, we discussed the reasons for the very considerable 
differences between the photogrammetric activities in the different countries 
of the world. There were marked differences even between the different orga 
nizations in Washington. 
First of all, we readily agreed that the differences were not due to differ 
ences in the level of intelligence of the several nations or organizations. The 
variations seem primarily due to two main causes. 
First. The variations in the ideas of what is needed most, in the objectives, 
especially in the way those needs are conceived by those who undertake to 
meet them. 
Second, (and most controlling) the “building blocks” of experience the 
small separate items of technical knowledge and skill available through each 
nation’s schools, laboratories and shops. The leading photogrammetrists of each 
country are limited in what they accomplish by the unit ideas they have exper 
ienced. Thus the unit “building blocks” ideas of technique, “building blocks” 
ideas or philosophy about what can be accomplished determine what actually 
is accomplished. 
Now, if the differences we observe were due to differences in the level of 
intelligence of the different countries or organizations, there is little that we 
could do about it. But every human mind does have the power to observe, to 
take advantage of new experiences; to consider two alternative courses of con 
duct in the light of its new, as well as its old, experiences; and to select its future 
course in the light of all the observations it has been able to make. 
To gain the widest exchange of new building blocks of experience is, of 
course, the main reason for our Congress. We of the American Hemisphere 
are exceedingly fortunate in that many of our most distinguished colleagues 
have traveled far at great expense to give freely of their ideas and to show us 
their admirable achievements. We in turn will be very glad if we can offer some 
building block ideas of our own needs; of our methods of organizing work; of 
our methods for attaining simplicity and reliability so essential for large pro 
duction. If I were asked what are the best building block ideas Americans can 
contribute to world Photogrammetry, I would say first, the idea of practically 
unlimited possibilities, the philosophy expressed in the American slogan “the 
difficult we do immediately, the impossible takes a little longer”. Second, the