> Camera is 
d for use in 
ographs for 
poses. The 
with Type- 
ch produces 
models are 
:6.3 lens of 
} has a f:6.3 
d the F-225 
ocal length. 
vith filters. 
23 & F-224 
e the F-225 
artographic 
essories for 
' operation. 
31 Vertical 
-228 Inter- 
29 Vertical 
i 
; 
for making 
rial photo- 
with perti- 
posure. The 
)ody and a 
nterchange- 
ly. It has a 
ply side is 
> by a light- 
t film load- 
ly designed 
the closely 
he ports on 
plate have 
tage of all 
Im flatness 
cone is of 
le because 
top surface 
ie with the 
‘ocal length 
ducial and 
's are illu- 
a recorded 
data card, 
rera serial 
, lens serial 
rated focal 
film move- 
lens Rapi- 
> never be- 
mera. The 
  
new Rapidyne precision-built shutter has 
a speed range from 1/10 to 1/500 second, 
a setting for lens calibration and a shutter 
  
    
   
   
   
   
PHOTOGRAMMETRIC ENGINEERING 43 
speed control on the outside of the camera. 
This shutter is interchangeable and can be 
replaced within a few minutes. 
IV. EDUCATIONAL AND SCIENTIFIC ACTIVITIES 
AMERICAN GEOGRAPHICAL SOCIETY 
The Society’s work in photogrammetry 
has been largely with photo-interpretation 
from the broad geographical standpoint 
and in the development of methods for 
making small-scale reconnaissance maps 
from oblique aerial photographs. As early 
as 1895, the Society was aware of the 
potentialities of photography in connec- 
tion with cartography and geography.! 
Twenty-one years later it began giving 
space in its quarterly, the Geographical 
Review, to articles on photogrammetry? 
and soon after started publishing articles 
and books on photo-interpretation.? 
The first expedition under the auspices 
of the Society which was equipped to take 
aerial photographs went into the field in 
1925.4 In 1930 the Society constructed a 
map of the Queen Maud Mountains from 
“high oblique” photographs taken on the 
first Byrd Antarctic expedition.’ Spurred 
on by the success of this venture it em- 
barked on a program directed by O. M. 
Miller, for developing practical means for 
making small-scale topographical maps 
from ‘high oblique” aerial photographs. 
The field work for this research program 
was undertaken in northernmost Labora- 
dor by an expedition organized and led 
by Alexander Forbes in the summer of 
1931. In the course of constructing maps 
from the ''high oblique" photographs ob- 
tained, systematic techniques were evolved 
and special instruments were designed 
and constructed.® The maps’ resulting 
from this experimental work covered 
about 5,000 square miles on a scale of 
1:300,000 with a 250 meter contour in- 
terval. In addition, sectional maps within 
the main area were produced on a scale of 
1:100,000 with a 50 meter contour interval. 
A considerable amount of reconnaissance 
mapping from ''high oblique" photographs 
involving unusual problems has since been 
undértaken at the Society. Notable are 
the sketch maps made without ground 
control from Leica photographs taken by 
Lincoln Ellsworth on his Trans-Antarctic 
flight in 1935.8 Another example is the 
map of the Sierra Nevada de Santa Marta 
made by Walter A. Wood in 1939.° This is 
somewhat unique in that all the work of 
constructing it, including the photogra- 
phy, was done by one individual. 
The difficult but useful art of sketching 
on small scales from large-scale aerial 
photography has also received attention. 
An outstanding example is the map of the 
Orinoco-Ventuari Region, Venezuela!? by 
Charles B. Hitchcock. In this, details were 
sketched in by eye, directly onto a radial 
line control plot which had previously 
been reduced to the scale of 1:500,000. 
The Society used ground photogram- 
metry first in 1933" and is continuing to 
use it especially in connection with its 
glacial studies.!? 
INSTRUMENTS AND METHODS 
The special instruments and methods 
used in the Laborador surveys have been 
described in the pages of PHOTOGRAM- 
METRIC ENGINEERING and elsewhere. Prin- 
cipal references are given in the appended 
bibliography. 
U.S.A. PHOTOGRAMMETRIC PATENTS TAKEN OUT BY THE AMERICAN GEOGRAPHICAL SOCIETY 
Title Inventor 
Stereoscopic Plotting of 
Date of Date of 
Number Filing Grant 
Contour Maps O. M. Miller 1985260 June 3, 1930 Dec. 25, 1934 
Mirrors Suitable for Map 
Plotting Devices O. M. Miller 2121255. Aug. 8, 1935 June 21, 1938 
Optical System O. M. Miller 2377509 Feb. 12, 1943 June 5, 1945 
Stereoscopic Mapping ; 
Instruments Theodore M. Edison 2444815 July 29, 1943 July 6, 1948