This paper briefly describes the basic Harwood apparatus, particularly its deviations from the original Bridgman model and the elaboration thereof by Birch for uses with gases at high temperature. Nearly all the physical measurements made by Bridgman at 12 kb can be made with this equipment at 30 kb, in some cases extending the temperature range.
The press portion of this apparatus lends itself to other high pressure procedures, extending the pressure range and increasing the scope of experimentation without great additional cost. New designs and techniques, some of which can be employed in a 14 kb isostatic environment, sometimes at elevated temperature, open many new paths of experiment, including some studies of extrusion, and the acoustic measurement of elastic constants.
Two new concept, the Harwood spherical anvils and the spherical cavity press are described. They are designed for pressures extending to 100 kb or more. The Harwood version of the Boyd-England apparatus, which can also be accommodated in the press, is described. Other more conventional devices have been accommodated in the press. Some are briefly mentioned, such as large chambers for more modest pressure.
Some of them are equipped with internal furnaces for temperatures ranging from 600 to 1500 oC.