Signedtyped in black on paper slip inside box: U.S. NATIONAL MUSEUM / Department of Geology. / Museum No. (none given) / Feldspar. / Locality: Topsham, Maine.
Inscribedhandwritten in pencil on paper slip inside box: Subjected to / pressure / Oct. 21 - 24, 1916
handwritten in pencil on top of storage box: 2 Feldspar / Cylinders.
FunctionHigh-pressure physics.
Oxford English Dictionary, 2nd Ed. "A name given to a group of minerals, usually white or flesh-red in colour, occurring in crystals or in crystalline masses. They consist of a silicate of alumina with soda, potash, lime, etc."
Historical AttributesPercy Bridgman's experimental work at Harvard University consisted mainly in the production of very high pressures and the investigation of the effects such pressures have on the properties of matter.
During the 1920s, most of Bridgman's experiments used high pressures between 12 000 and 20 000 atmospheres (12,000-20,000 kg/cm²). In order to produce such high pressures, Bridgman used a hydraulic press in conjunction with two pumps in order to produce the high pressures. See for example, 1997-1-1819a, b, c and d.
During the 1930s, Bridgman increased the pressure, reaching between 30 000 and 50 000 atmospheres using two and even three hand pumps.
Bridgman would put samples of various materials into a chamber of the press, raise the pressure inside the chamber, and then study the material samples or residues that remained afterward. He the effects of high pressures on the specific resistance, temperature coefficients, volume, electrical conductivity, shearing strength, electrical resistance, density, tensile properties, and compression. He studied these effects on all manner of substances from minerals, metals, and chemicals to plastics, glass and egg yolks. Bridgman hoped his experimental results would contribute to theories of the internal structure of atoms and molecules that were gaining attention throughout the first half of the 20th century. He was awarded the Nobel Prize for Physics in 1946 for his research.
Bridgman also did work on the synthesis of diamonds from graphite using very high pressures and temperatures. Early in 1941, the General Electric Company arranged a five year agreement with Bridgman to finance his experimental research in producing diamonds. Bridgman wanted to reverse a known process in which diamonds turn to graphite at atmospheric pressure and 1500°C. His experiments were conducted in the Harvard Geophysical Laboratory. However, Bridgman was ultimately unsuccessful in the synthesis of diamonds, and his continued research was interrupted by the outbreak of the Second World War.
Primary SourcesAbbot, C.G. The Experiments of Dr. P. W. Bridgman on the Properties of Matter When Under High Pressure in Smithsonian Report for 1918. Washington: Government Printing Office, 1920. pp. 185 - 204. (Lib. 2912)
Bridgman, Percy W. Mercury resistance as a pressure gauge. Physics Research Thesis at Harvard University (in Harvard University Archives), 1910.
-------------------------- A condensed collection of thermodynamic formulas. Cambridge: Harvard University Press, 1925.
-------------------------- Physics of High Pressures. London: Bell, 1931.
-------------------------- "Shearing phenomena at high pressure of possible importance for geology" in Journal of Geology, Vol. 44 No. 6 (1936), pp. 653 - 669.
------------------------- Studies in Large Plastic Flow and Fracture. New York: McGraw Hill, 1952.
-------------------------- "Certain Aspects of Plastic Flow under High Stresses" in Studies in Mathematics and Mechanics Presented to Richard von Mises. New York: Academic Press Inc., 1954. pp. 227 - 231. (Lib. 5817)
-------------------------- "Effects of Pressure on Binary Alloys" and "Miscellaneous Effects of Pressure on Miscellaneous Substances" in Proceedings of the American Academy of Arts and Sciences, Vol. 84, No. 1 (1955).
-------------------------- "Synthetic Diamonds" in Scientific American, November 1955, pp. 42 - 46. (Lib. 340)
------------------------- Collected Experimental Papers. Cambridge: Harvard University Press, 1964.
ProvenanceFrom Professor Percy Bridgman, Department of Physics, Harvard University.
Related WorksKenble, Edwin C. & Francis Birch. Percy Williams Bridgman, 1882 - 1961. A biographical memoir. New York: Columbia University Press, 1970.
Walter, Maila L. Science and cultural crisis: an intellectual biography of Percy Williams Bridgman (1882 - 1961). Stanford, CA: Stanford University Press, 1990 [1985].