— 45 
I he Radial Secator is a further developed slotting apparatus for mecha 
nical radial triangulation. Aerial photograph and template are lying in two 
storys centered above each other; the scale ratio between them can be varied 
within wide limits. Tilted pictures can be automatically rectified during the 
punching process. 
The newly constructed Mirror Stereoscope « Stereotop » consists ot 
three component stages : 
I. — Simple Mirror Stereoscope (to which a Stereometer can be 
added). 
II. — Stereoscope (model I) with parallel guides and built-in stereo 
meter. 
III. — Parts of model I and II with additional automatic correction of 
tilt errors of the optical model and connection to Pantograph. 
( 
Models II and III can be always complemented from model I, resp. II, 
by addition of the extra attachments. With this equipment any job ranging 
from simple stereoscopic topographical plotting can be easily handled. 
Rectifier SEG V is a completely new construction of highest optical and 
mechanical performance. It is suitable for high-precision rectification at large 
scale as well as for quick and economic work at small scale. The first purpose 
is served by the large projection table which if freely accessible from three 
sides, the newly developed illumination system, the distortion-free and high- 
power Topogon as well as the vanishing-point-control (besides two invertors 
for achieving sharp projected pictures). For extensive working conditions 
the pre-calculated settings are introduced at illuminated scales, further-on 
an automatic exposure timer has been provided. The range of magnification 
is from 0.5 to 6.4 times. In spite of this the minimum structural height is 
only 2.0 m. 
2°) FRANCE 
a) MÉTHODE DE FORMATION DE L’IMAGE PLASTIQUE par 
M. G. Poivilliers, Membre de l’Institut. 
La méthode est un perfectionnement de celle exposée au Congrès de 
La Haye en 1948. Elle est, comme celle-ci, basée sur le fait que la correction 
de la parallaxe transversale dans un plan perpendiculaire à la base est une 
opération de « relèvement ». 
Dans cette nouvelle méthode les segments capables sont remplacés 
chacun par une corde passant par deux points voisins du segment corres 
pondant.