GV-88 PHOTOGRAMMETRIC ENGINEERING 
and expression record. It is practically an automatic process. It requires only the 
starting and stopping of the traveling motion picture camera. No adjustments 
are required on the camera and lights for the different subjects, as the distance 
of the subject from the camera, the size of the stop opening, and the exposure 
time are always the same for all subjects. Once the camera is set, it remains 
set. Photographic knowledge is not needed for making the photographic rec- 
ords. 
THE CARVING OF AN ALL-AROUND SCULPTURED PORTRAIT 
Having the form and expression record, the question is how to make from 
the two-dimensional, flat pictures, a three-dimensioned sculptured portrait. 
This is easily answered. The portrait is carved out in as many different planes as 
contour pictures were made of the subject. Each plane has its own picture, to 
  
  
Fic. 4. Carving device for sculptured all-around portrait. 
which it is mechanically connected, so that a mix-up is impossible. Figure 4 
shows a carving device in operation. The photographic record is placed into a 
projector—a part of the carving device—and the various contour pictures of 
the record are projected upon a screen, one by one, as still pictures and to the 
size required. This size depends upon the size of the portrait wanted. 
The amount to be removed from the material block for each section of the 
portrait is clearly indicated by its outline on the projected picture, and by the 
transparent area outside the picture. The connection between the projected 
screen picture and the material block is made by a pantograph which at its 
one end has a tracer point, and at the other end a revolving cutter driven by a 
small electric motor. The operator traces the picture outlines by following them 
with the tracer point of the pantograph. These movements are transferred by 
the pantograph to the rotating cutter, which cuts away from the block all 
surplus material, and leaves only an area unremoved at the cutting plane of the 
material block, which has the same shape as the copied contour picture used. 
The entire carving process is a simple milling operation, in which the cutter 
is always moved in the same cutting plane for the entire portrait, and the block 
is moved in and out of the cutting plane, angle by angle. 
A simple turn of a handwheel projects a new outline picture on the screen,