May, 1960 Commission VII 193 
INSTRUMENTAL DEVELOPMENT 
The use of photogrammetry for 
many special measuring purposes is 
hampered greatly by a lack of suitable 
cameras, lenses, and other equipment. 
The design of a group of distortion- 
free lenses was started at N.R.C., but 
only one lens has been completed so 
far, owing to lack of personnel. Figure 
7 shows the camera set-up for this lens. 
The cone is removable to permit the 
use of different lenses, and the table 
can be shifted accurately to introduce 
a base for stereo pictures. The National 
Research Council intends to continue 
with the design of lenses and other 
equipment for special applications of 
photogrammetry. 
Fic. 7 
  
COMMISSION VII 
PHOTO-INTERPRETATION 
by S. T. B. LosEk 
The largest use of aerial photographic interpretation in Canada is still by a wide 
margin in forest surveys. In this field it won secure acceptance many years ago, and 
during the past four years its use has been marked by a widespread application of 
tried and tested procedures well adapted to the required end of forest inventory. The 
next advance demanded is the application of aerial photographic interpretation to detailed 
forest survevs of small areas to obtain estimates of timber volumes of high accuracy, 
but only one organization, as far as the writer is aware, is seriously working towards 
this end. 
Soil interpretation from aerial photographs is undoubtedly second in the extent of 
its use in Canada. The forest industry is prominent in this field also, both in connection 
with the studies of soil values for forest growth, and in connection with its large road- 
building program. Provincial and Dominion departments of Agriculture are active 
in this field, in their studies of farming problems. Engineering organizations such as 
government highway departments, consulting firms, and large construction companies 
rely heavily on photographic interpretation in the location of highways, dams, and 
airports, in the search for construction materials, in the study of irrigation projects, and 
in many other types of engineering.