at 
consid- 
mise 
Or 
ie of 
.ned 
ptable 
indeed, 
e that 
>ans 
1e 
lps. 
> use 
ceding 
On the 
likely 
er- 
Y 
nal 
An 
n- 
r II's 
tematic 
ent 
) recent 
sing. 
on a 
+ 
photo 
this 
trending, we would better know what to do, and how to do it." Hope- 
fully this paper of mine has provided a sufficient insight as to 
"where we are and whither we are trending" in the field of photo 
interpretation that it will provide some highly useful indications 
to us of "what to do and how to do it" as we look forward confi- 
dently to another 25 years of progress in photo interpretation 
under Commission VII. 
Literature References 
American Society of Photogrammetry "Manual of Photographic Inter- 
pretation" 896 pages, illustrated. George Banta Co., Menasha, 
Wisconsin, 1960. 
American Society of Photogrammetry "Manual of Remote Sensing" 
2144 pages, illustrated. Keuffel and Esser Co., 1975 
Colwell, Robert N., "Report on Commission VII (Photographic 
Interpretation) to the International Society of Photogrammetry." 
Photogrammetric Engineering, Vol. 18, pp. 375-400, September 1952. 
Colwell, Robert N., "The Future of Photogrammetry and Photo 
Interpretation". Photogrammetric Engineering, Vol.25, pp.713- 
736, December 1959. 
Colwell, Robert N. "Some Recent Developments of Basic Significance 
for Photo Interpretation" In Proceedings of Third Regional 
Cartographic Conference of the United Nations, Bangkok, 
Thailand, 23 pages, October 1961. 
Colwell, Robert N., Schrumpf, B., and Poulton, C.E., "The Reduction 
of Remote Sensing Data by Visual Means" In Proceedings of NASA- 
Sponsored Conference of Remote Sensing Educators, Stanford 
University, 61 pages, June 1978. 
Committee on Remote Sensing, "Basic Matter and Energy Relationships 
Involved in Remote Reconnaissance" Photogrammetric Engineering, 
Vol. 29, pp. 761-799, September 1963.