STEREOPHOTOGRAMMETRY AND STUDIES OF MOVEMENTS 
by M. ZzrrER, Zurich, Switzerland. 
For years the manual movements in certain working processes have been taken | | 
cinematographically or by the so called light points, process. The latter method | t0 IH 
consists in photographing the course of smali lamps fixed to the body, especially to | 
the hands of the person in 
question. By both these 
methods we obtain a clear 
picture of the movements | 
executed; they do not, howe- | 
ver, permit of a sufficiently 
accurate determination of 
their form and especially of 
their strewing. For the study 
of the economy of working 
processes an exact knowledge 
of the spatial curves of the 
single movements and their 
strewing, and consequently 
the possibility of a compari- | 
son with other working dis- 
positions is necessary. Only 
this possibility to compare 
permits of ascertaining the 
most favourable working 
conditions with regard to 
length of way and form. 
Fig. 1 shows a working 
place in the laboratory of 
the Industrial Management 
Institute of the Swiss Fede- 
ral Institute of Technology 
at Zurich. The symmetrical 
arrangement allows to study 
the movements of both hands 
at the same time. The ope- 
rator, provided with incan- 
descent lamps on both hands 
1s shown working in Fig. 2. 
To review the total movements her head and shoulders are likewise provided with 
incandescent lamps; Fig. 3 shows how her movements are subsequently marked by 
the course of the lamps. 
For the task in question the “Wild” stereo-camera of a basic length of 40 cm 
was used (Fig. 4 and 5) by which a plotting exactitude in the scale of 1 :2 of about 
1 mm is obtained for taking distances up to about 4 m. 
In studies of movements another light signature has to be chosen for every 
mmm