298 
Photogrammetry in surveying of liquids in motion 
It was proposed to the Istituto di Topografia e Geodesia of the University of Trieste, the 
problem of surveying the surface of a liquid in motion in an experimental canal, where some 
obstacles were set which perturbed the regular movement of the liquid, and gave to its surface 
an appearance characterised by vortices and complicated waves. 
For the photogrammetric survey of the free surface of the liquid, two cameras of the Multiplex 
Zeiss instrument, belonging to the Institute, were employed; they were held in normal position on 
the canal, by using a support similar to that of the original plotting apparatus. 
Simultaneous exposures were obtained by means of an electronic flash. The liquid’s surface was 
made visible by paraffin powder thrown on it with a special apparatus, immediately before taking 
the exposures. 
The model was plotted by rigorous application of Porro’s principle, with the same cameras 
employed for the exposures, drawing contours by means of anaglyphes. 
La séance est levée. 
Compte rendu de la séance du 25 juillet 1956, 
à 13.30 heures 1 
W. F. Engelmann: 
Photogrammetry applied 
to making 
sculptured portraits. 
(Publ. V E 1; 
voir USA V) 
Halsman 
Le Président ouvre la séance et demande à M Uo V. Weir de présenter les com 
munications de MM. Vm. F. Engelmann, Etats-Unis, et T. E. Blesh, Etats-Unis, 
pas présents. 
Résumé de la communication de M. Engelmann: »Photogrammetry applied 
to making sculptured portraits». 
To make a sculptured portrait, a highly trained sculptor is required and a 
willing subject who is not averse to »sit» many tedious hours for the sculptor. 
Thanks to Photogrammetry, this is all changed now. The sculptor’s eye and 
memory are replaced by photography, and his trained hands by new and up-to- 
date tools. The subject has to sit for only a fraction of a minute. The portrait 
can be of any size, any design, and any material; from the largest of bronze for 
monuments, to the smallest of gold for jewelry. Last but not least, a good and 
pleasing likeness, can now be guaranteed which is the most important quality 
of a sculptured portrait. 
Two steps are required for making a sculptured portrait by this new method: 
The making of a »Form and Expression Record» of the subject and the carving 
out of the portrait from a large material block. 
The record consists of a strip of motion picture film, which shows a series of 
contour pictures of the subject’s head and neck. It is made by photographing 
the subject with a slowly traveling motion picture camera, while a sharply 
defined shadow edge is moved over his head and neck. This moving shadow 
edge reveals in its path all configurations of the subject’s features which the 
traveling camera photographs. 
The photographic record is placed into a projector and the pictures imaged 
on a screen to any desired size. The outlines of these projected pictures are 
then used as guide lines for carving out the portrait in as many planes as 
contour pictures were made of the subject. 
Apart from the fraction of a minute it takes to get the form and expression 
record made, all tedious sittings of the subject for the sculptor are thus 
eliminated. 
The carving of the portrait is done with the help of a pantograph which has 
one arm equipped with a tracer pin and the other with a rotating cutter driven 
by an electric motor. Moving the tracer pin anywhere outside the projected 
contour picture forces the cutter to cut away all surplus material from the 
1 During this session a paper by Mr. J. Halsman, USA, on »Stereoscopic medical photography» 
was also read by title. See further publication V: H‘2 in USA V.