wrenches for Bridgman press
Date1924-1937
Inventory Number2004-1-0404.3
ClassificationWrench
Subject
Maker
Percy Williams Bridgman
1882 - 1961
Maker
Crosby Steam Gage & Valve Company
fl. 1880s - 1930s
Cultural Region
Place of Origin
Place of Use
Dimensions189 x 107 x 75 cm (74 7/16 x 42 1/8 x 29 1/2 in.)
Material
Accessoriestwo boxes of parts/tools for bridgman press (.1 & .2)
DescriptionA hand-activated Bridgman high-pressure press mounted on a rectangular wooden box with two open ends, standing on four wheels. According to the accompanying manual, the press is designed to be used with two hand pumps. One, with a red base, is mounted on the top of the wooden box stand. The other, with a yellow base, is stored inside the wooden box stand.
The main components of the press apparatus are the pistons and cylinders supported by vertical steel rods. The main piston and main cylinder are near the bottom of the steel rods and a pressure intensifier piston is above. Pressure is built up in a steel chamber by moving the lever of each hand pump up and down. The yellow hand pump is attached by copper tubing to the main piston. The red hand pump is attached by copper tubing to the pressure intensifier piston. The accompanying manual provides detailed instructions for alternating between the red and yellow hand pumps in order to create the most pressure. At the bottom of the main cylinder is a length of copper tubing that connects to the pressure gauge. The pressure gauge's units are in pounds per square inch, from 1 to 15,000. Another copper tube goes from the bottom of the main cylinder to an optical cell.
Various extra parts, lengths of tubing and wire, and other miscellaneous items are stored in the wooden box stand. The box is trimmed with metal strips with holes punched through.
The main components of the press apparatus are the pistons and cylinders supported by vertical steel rods. The main piston and main cylinder are near the bottom of the steel rods and a pressure intensifier piston is above. Pressure is built up in a steel chamber by moving the lever of each hand pump up and down. The yellow hand pump is attached by copper tubing to the main piston. The red hand pump is attached by copper tubing to the pressure intensifier piston. The accompanying manual provides detailed instructions for alternating between the red and yellow hand pumps in order to create the most pressure. At the bottom of the main cylinder is a length of copper tubing that connects to the pressure gauge. The pressure gauge's units are in pounds per square inch, from 1 to 15,000. Another copper tube goes from the bottom of the main cylinder to an optical cell.
Various extra parts, lengths of tubing and wire, and other miscellaneous items are stored in the wooden box stand. The box is trimmed with metal strips with holes punched through.
Signedembossed on a black plaque screwed to side of red hand pump: MODEL NO. P228 / SERIAL NO. 6.391604 / SPEED R.P.M. / CAP. LBS, SQ. IN. / 40000 / BLACKHAWK MFG. CO. / MILWAUKEE, WIS. U.S.A.
etched in black on face of pressure gauge: CROSBY / BOSTON U.S.A. / AIH / LBS. PER SQ. IN.
Inscribedhandwritten in black on two strips of masking tape on side of wooden box: BENEDEK 8/16/8
handwritten in black on two strips of masking tape on side of wooden box: BENEDEK
handwritten in black pen on lid and side of cardboard storage box with extra parts: Bridgman / Press
Curatorial RemarksThis object is accompanied by a CD containing 27 photographs of this press being explained and demonstrated by George G. Benedek, a physics professor at MIT who also used it and a cassette tape with a recording of that demonstration. MIT also printed a user's manual for this press which is available as a PDF document through this data entry.
On May 11, 2011, a film was taken at Fine Arts Express (the CHSI off-site storage location) of Gerald Holton, Mallinckrodt Professor of Physics and emeritus Professor of the History of Science, with this press, discussing its operation and recounting stories of Percy Bridgman.
FunctionThis press was used to exert high pressures on metals and other materials to test the effects of high pressure on the properties of matter. Bridgman, for instance, measured compressibilities, electrical resistances, viscosities and later, with the higher pressure apparatuses, the effect of pressure on the mechanical strength and ductility of these substances (which were very large).
This press was one of Bridgman's later models, produced in the second half of the 1930s that used two hand pumps to achieve higher pressures. In the 1920s he achieved pressures that ranged between 12,000 and 20,000 atmospheres (12,000-20,000 kg/cm²). In the second half of the 1930s, Bridgman expanded his range of pressures with more powerful hydraulic presses, reaching between 30,000 and 50,000 atms (see #1997-1-1819a). To achieve this higher pressure, two and even three hand-pumps were required, each activating a separate compressing piston. According to a plaque on the red hand pump, this press could reach 40 000lb/in² (46 085 kg/cm²).
This press was one of Bridgman's later models, produced in the second half of the 1930s that used two hand pumps to achieve higher pressures. In the 1920s he achieved pressures that ranged between 12,000 and 20,000 atmospheres (12,000-20,000 kg/cm²). In the second half of the 1930s, Bridgman expanded his range of pressures with more powerful hydraulic presses, reaching between 30,000 and 50,000 atms (see #1997-1-1819a). To achieve this higher pressure, two and even three hand-pumps were required, each activating a separate compressing piston. According to a plaque on the red hand pump, this press could reach 40 000lb/in² (46 085 kg/cm²).
ProvenanceProfessor George Benedek, MIT.
Historical AttributesThis high-pressure press was constructed and by Percy Bridgman and also used by George Benedek in the Physics department at MIT.
Percy 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. 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 <i>specific resistance, temperature coefficients, volume, electrical conductivity, shearing strength, electrical resistance, density, tensile properties,</i> and <i>compression</i>. 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.
Percy Williams Bridgman
Date: 1924-1937
Accessories: cardboard box of spare parts; rubber tube; yellow hand pump; metal wire; torque wrench; wrenches (3); 1 CD; 1 audio cassette; 1 user's manual; 1 graph
Object number: 2004-1-0404
Percy Williams Bridgman
Date: 1924-1937
Object number: 2004-1-0404.1
Percy Williams Bridgman
Date: 1924-1937
Object number: 2004-1-0404.2
Percy Williams Bridgman
Date: circa 1924
Accessories: high-pressure compressing chamber
Object number: 1997-1-1819d
Percy Williams Bridgman
Date: 1924-1937
Accessories: pressure-broken metal samples; parts for hydraulic press
Object number: 1997-1-1819c
Percy Williams Bridgman
Date: 1924-1937
Accessories: 4 wrenches; 1 oil pan
Object number: 1997-1-1819b
Percy Williams Bridgman
Date: circa 1938
Accessories: one bolt protector; one attachment; two large bolts, black and white photographs (C6-G1). Parts can be found in drawer B11-I8. Bridgman Press Manual (copy) in instrument file folder
Object number: 1997-1-1819a
Hammond Typewriter Company
Date: circa 1923
Accessories: four Hammond type shuttles for different type faces, each with a wooden storage box; four laminated paper rectangles with symbol placement guide; instruction book, instruction sheets, advertisements, and correspondence (in object file)
Object number: 1996-1-0373
Parent/Child
