A furnace has been designed to fit the Philips x-ray diffractometer. The temperature may be raised at a uniform rate or maintained at a controlled level from 0° C. to 1000° C. Powdered crystalline materials are placed on a Pt-Rh plate which rests on a heating element near the center of the furnace. The temperature is recorded by a Pt, Pt-Rh thermocouple connected to a Brown recorder. Variations in intensity and angle of reflection for oscillations or scans are charted on a second Brown recorder synchronized with the temperature recorder. The back of the furnace contains a water jacket for cooling while the front assembly is enclosed by an inconel cover. The insertion of a beryllium window permits controlled atmosphere experiments. Arkansas quartz has been used to ascertain the temperature characteristics of the furnace and to obtain data on the alpha-beta lattice expansion with its accompanying intensity changes.