te orientation by 
tation by calcula- 
it with the multi- 
| few models, the 
eport a graphic 
' deformations of 
ited in a “bridge” 
hod is used, con- 
o the base at the 
fell in ideal loca- 
metimes a second 
cally never for a 
ls. 
the plotting pro- 
changes from the 
ne parameters of 
and inexact plot. 
ench IGN uses 4 
he IGM of Brus- 
mental work. 
| A6; in Sweden 
rlands, type A6; 
; A5 and A6 and 
e the A5 and the 
| IV and Stereo- 
ctical studies, in 
talian IGM still 
AL uses Models 
1y years, but in 
type which, like 
Austria, U.S. A. 
older types, the 
en has built the 
rent versions in 
(357) 
The Bausch and Lomb multiplex is used in USA and Canada, which also 
uses the Williamson. 
Nistri has made a new model of the Multiplex, No. 4 with electric driven 
tracing table and coordinatograph as in the preceding model. : 
In the simplified class are both old and new apparatus; some stereoscopic 
plotters for tracing contours; others only planimetric plotters with automatic 
corrections for presumably known relief (Class A). Some use rectified negatives 
or positives (Class B) others use the original negatives and neglect their tillt 
Class €. 
In Class A the pantograph plotter of M. Dubuisson is used by the French 
Ministry of Reconstruction and City Planning. Germany reports different sim- 
plified apparatus: The Klein Autograph for terrestial work and non-topogra- 
phic plotting; the proposed construction of a “Panagraph” working by mechani- 
cal projection but sull only a project; the Stereo-pantometer, composed of a 
mirror stereoscope and a stereometer reading the parallaxes. The Kern Ortho- 
stereometer uses essentially a mirror stereoscope and has in 1952 three types 
called Simplex. Model 1 is a simple mirror. Stereoscope Model II carries a paral- 
lax bar and Model III includes a corrector for tilt of the stereoscopic model. 
Finally announced is a second order apparatus with two projectors using the 
Porro Koppe principle and the double projection of the original photographs; 
observation with an ordinary stereoscope or by anaglyphs. 
Canada reports the use of the Wehrnsted-Mahan plotter, Sketchmasters 
and the Seelyscope. 
The USA reports use of differing simple plotters: the Kelsh Plotter, the 
K.E.K. Plotter, the Ryker PL3, the Reading Plotter, this last using multiple 
photographs taken with the nine-lens camera of the Coast and Geodetic Survey 
after transformation of the 8 wing pictures to the plane of the central one. 
The Italian report cites the Nistri Stereographometer (Model 18 X 24 and 
13 X 18) also Nistri stereoscope with stereometer as used for 1 : 25,000 scales 
and smaller in Arfica and for the surveys of the coast of Somaliland by the 
Hydrographic Service. 
The Hydrographic Service of France has used the KEK plotter. 
When one studies objectively the actual situation of plotting apparatus, 
one cannot but be struck by the small number of universal plotters of which 
the older models reappear for twenty odd years and for which the different 
models differ only in detail (the Stereotopographe Poivilliers Model D is a rare 
exception to this rule); on the contrary the simple apparatus, despite their 
inconveniencies, their low accuracy, their reduced possibilities are much more 
numerous and new ones are continually being seen; evidently the possible solu- 
tions are limited in number and these devices seem also of a small number of 
families; but their low cost is without doubt the basis of this infatuation for 
simple apparatus; moreover, it is the only advantage one can recognize for 
them. 
Supplementary Operations on tbe Ground. 
In the USA according to circumstances, a numer of notes are made on the 
ground before the plotting and the map is published without any further work 
on the ground, or better this work is done after the plotting. Only for large