Abstract
Formerly, FENART (1969) developed a small and portable - X-ray tomograph, called the vestibulograph, which was designed for craniological study based on the vestibular plane. This apparatus seemed to be suitable for use in ordinary anthropological laboratories. However, he did not explain the principle of making a tomogram with this apparatus. The authors also needed such a small tomographic apparatus and so searched for the principle used in producing FENART's apparatus. The fundamental condition was that the object and the film rotate completely parallel within a range of angles. The authors clarify and describe in this paper the principle of tomography of this type based on this condition. The authors also manufactured an acutal apparatus using this principle and tested it by taking tomograms.
