4 
Urban, F. Checks on Two Foot Contour Mapping. Vol.3,No.i, 
J une,I 967 
Williams, H.S. The Propagation of Error in Aerial Triangulation of 
Strips. Vo I .2No.3,May,1965 
Model Deformations resulting from the Orientation 
and Scaling Procedures. Vol.3,No.I,June,1967 
III South African National Survey Conference, January 1967 
Thorpe, J.A. Systematic and Random Errors in Aerial Triangulat 
ion. Paper 3/51 
Williams, H.S. and Polynomial Forms in Aerial Triangulation Adjustment. 
Belling, G.E. Paper 3/16 
Photogrammetric Engineering 
Williams, H.S. and Hybrid and Conformal Polynomials. Vol.XXXI I I,No.6, 
Bel ling, G.E. Oct.,1967 
Proceedings of First and Second Symposium on Soil Surveying, Mapping 
and Data Storage. S.A.I.C.E., September, 1964 and December, 1965. 
COMMISSION VII. PHOTO INTERPRETATION 
Rapporteur: Mr. T.C. Partridge 
Strong emphasis has been placed on the earth sciences particularly geo 
logy and pedology. The entire Beaufort Series of the Karroo System 
has been mapped geologically with the emphasis on structural patterns. 
Considerable refinements have been achieved in interpretation methods 
in the preparation of soil engineering maps for road projects. The 
degree of correlation of certain classes of landform with soil mater 
ials having specific engineering properties has been particularly 
significant. Colour transparencies have in .some cases greatly facili 
tated pedological interpretation, but true colour rendition is difficult 
to achieve and if not achieved may greatly detract from the accuracy 
of interpretation. 
The Department of Agriculture makes extensive use of aerial photo 
graphy for soil and vegetation classification as well as conservation 
planning. The National Building Research Institute assesses slopes, 
drainage patterns and soil types by means of interpretation procedures, 
while the Department of Forestry uses both panchromatic and infra-red 
photography in identifying indigenous tree species and general forest 
planning. Large scale photography has been used in a census of bird 
and seal populations of small rocky offshore islands. 
Recent photography at scales of up to 1/80000 using wide and supei 
wide angle lenses for survey purposes is of limited use to the photo 
interpreter and attempts are being made to satisfy his demands with 
larger scale photography.