HISTORICAL EXHIBITION 39 
Exhibit 45* 
Exhibit 46 
Exhibit 47 
Exhibit 48* 
Exhibit 49 
Exhibit 50 
Exhibit 51 
(Lent by the Ottico Meccanica Italiana e Rilevamenti Aerofotogram- 
metrici SpA). 
Aerial photograph of Venice from a balloon, 1911. 
(Lent by the Ottico Meccanica Italiana e Rilevamenti Aerofotogram- 
metrici SpA). 
Photogrammetry up to the Early 1940’s 
Autoriduttore Santoni, 1921. 
The first plotting instrument with mechanical materialization of rays 
without stereoscopic vision. 
(Lent by the Istituto Geografico Militare, Florence). 
Wild Autograph, Al, 1924. 
The first Wild plotting machine for terrestrial photographs taken with a 
phototheodolite with horizontal, tilted or laterally inclined camera axis. 
The binocular telescope of the Autograph can occupy a horizontal or an 
inclined position. But it remains fixed during plotting, whereas the plate 
carriers, each connected to a guide rod, are moved. In order to eliminate 
projection errors arising from this method, the photographic plates are 
automatically rotated by an ingenious correcting system, the basic inven 
tion of the Wild patents. The autograph operates with polar coordinates. 
British Patent 168,071 (1920). 
(Lent by Wild Heerbrugg, Ltd, Switzerland). 
Photograph of Laussedat’s transformateur photogrammétrique. 
Intended for rectifying photographs taken from the air. 
(Lent by the Conservatoire National des Arts et Métiers, Paris). 
Canadian photogrammetric elevation calculator, 1916. 
Used to determine from photographs the elevations of various points 
surveyed. It provides settings for the focal length of the camera and the 
elevation of its optical axis above the datum level, for the distance of the 
picture-point from the horizon line of the photograph and for the distance 
of the corresponding point on the plan from the photographic trace line. 
(Lent by the Science Museum, London). 
Hugershoff microscope comparator, c 1919. 
Constructed by G. Heyde - Aerotopograph - GmbH, Dresden, for 
13 cm X 18 cm transparencies. The plate is viewed through the observing 
microscope which can be moved parallel to the plane of the plate in two 
directions at right angles one to the other. The amount of movement is 
read on x and y scales by measuring microscopes. The plate can also be 
rotated so that the principal horizontal axis can be aligned parallel to 
either the a or the y scales. 
(Lent by the R. E. Equipment Branch, War Office, England). 
McLeod tilt-finder, Mark I, 1922. 
This early model is only suitable for use in flat country, when the control 
points are all of the same height; in other cases the tilt has to be found 
by successive approximations. 
An eye-hole forms the perspective centre and the plane of the map is 
represented by a movable glass screen on which the control points are 
plotted. The air photograph is placed behind the screen and the screen 
and photograph adjusted until the control points on the screen are in 
perspective from the eye-hole with their images on the photograph. A 
‘perpendicular indicator’ is then placed on the screen and moved until