For the purpose of obtaining characteristic X-ray patterns continuously from an arbitrary line element on the surface of a specimen having some local irregularities or changes, a camera of a new type has been designed. This camera is cylindrical, inner diameter 54 mm, outer 60 mm and length about 80 mm, and the primary X-ray beam is introduced parallel to the cylinder-axis but 10 mm apart from it. Both pinhole-system and cylindrical shield are fixed, while cylindrical cassette for photographic film, and cylinder cap for specimen are capable to rotate about the cylinder axis as ore body. The photographic film is inserted innerside of the cassette which is then covered by the cap. The specimen is fixed to the stem, of which the axis coincides with the rotating axis and which is faced to the cap. The shape of such specimen is of a truncated circular cone, and every part on the surface of the zone 10 mm apart from the axis is irradiated by the X-ray beam through the pinhole-system, fixed to the camera body. In order to protect the photographic film from undesirable blackening, both the pinhole-system and the specimen are covered by the cylindrical shield having a long slit, 1 mm in width and parallel to the axis. When the specimen and the photographic film are rotated during the exposure, the obtained patterns will take the form of several continuous lines.
These characteristics of this camera were confirmed by an experiment on partly hardened steel obtained using high frequency induction. In this way the present author has obtained patterns consisting of nearly straight lines having several diffuse and broken parts due to irregularities in the irradiated parts of the specimen.
