(4) 
for air photogrammetry. Among other noteworthy achievements of earlier 
days may be mentioned the mapping of the International Boundary through 
the Rockies, and, more northerly, of the boundary between Canada and Alaska. 
This work was carried on under the supervision of Dr. W. F. King, a former 
colleague of Deville who became the first Dominion Astronomer. Other well- 
known pioneers who carried on extensive surveys by the Deville system were 
A. O. Wheeler and M. P. Bridgland, and later work has been done by the British 
Columbia Department of Lands and Forests. 
Probably the most spectacular application of Deville's svstem in Canada 
was the mapping of the crest of Niagara Falls in 1927, by W. H. Boyd where 
vertical air photography was used for the base map (Ref. 27). 
In Canada graphical methods for plotting from the photographs have 
always been favoured, and a number of ingeneous office devices of a simple 
nature have been invented for application to the Deville system and these 
increase the efficiency of the operations. The present Deville type camera is 
all metal, and can be set interchangeably with the telescope in the standards of 
a small conventional transit or, alternatively, mounted above the telescope of 
a Wild T2 theodolite (Ref. 20). 
While Deville was one of the first to realize the possibilities of stereo- 
photogrammetry (he had presented a paper on the subject before the Royal 
Society of Canada in 1896, as a result of which Pulfrich actually built a plotting 
instrument along the lines suggested (Ref. 7) no practical use was made of 
stereo measurements in Canadian ground photogrammetry, although, quite 
early, a Zeiss photo-theodolite and a Pulfrich stereo-comparator were acquired 
for experimental purposes. 
THE GENESIS OF AIR PHOTOGRAMMETRY IN CANADA 
Shortly after the end of World War I, in 1919 a government committee 
known as the “Air Board” (Ref. 1) was formed under Act of Parliament to 
supervise and develop aviation in Canada. In 1920 we find the first record of 
a mosaic from air photographs being made for the Board in the Surveyor General's 
office (Ref. 4). The Board sought ways in which the use of aircraft might be 
applied in economic developments, and its Secretary, J. A. Wilson, an engineer, 
recognized that mapping might be one of these. In 1920 he consulted Deville 
regarding the possibilities and although, at first, the latter did not display much 
enthusiasm Wilson finally obtained his support, and the Surveyor General 
himself became a member of the Board in 1920 (Ref. 2 and 3). 
At about this time a number of experiments in air mapping were made in 
Canada. The earliest in which Deville participated being those of Professor 
H. L. Cooke of Princeton University, U.S.A., which were carried out in the 
summers of 1921 and 1922. Cooke had built at Princeton a rectifying and pro- 
jection apparatus based on the flicker principle for producing fully contoured 
maps. He wished to test, in the vicinity of Ottawa, two wide-angle plate 
cameras which he had constructed to obtain the photographs. A fairly complete 
account of the investigations of Cooke and of Deville is to be found in Ref. 3. 
      
  
  
  
  
  
  
  
  
  
   
  
  
  
   
  
    
  
   
   
   
  
  
  
  
  
  
   
   
  
  
   
  
  
   
   
    
    
  
   
  
    
   
    
   
   
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