Differential Analyzer Parts and Documentation

Room-sized differential analyzers were among the largest computing devices built before the advent of mainframe computers. The first was completed in 1930 by Vannevar Bush and his associates at MIT for use in solving a wide range of second-order differential equations of practical importance. Further funding from the Rockefeller Foundation made possible the building of an improved differential analyzer at MIT, with the original going to Wright University in Dayton, Ohio. Differential analyzers also were built for ballistics calculations at Aberdeen Proving Ground, for astrophysical research in Norway, and at Cambridge and at Manchester in England. Several differential analyzer components in the Smithsonian collections come from a differential analyzer built after World War II by General Electric for the University of California at Los Angeles and used extensively in the design of aircraft.

This wooden box with a glass front contains two of the six original integrators from the differential analyzer designed by Vannevar Bush (1890-1974) for use in the electrical engineering department at MIT.
Description
This wooden box with a glass front contains two of the six original integrators from the differential analyzer designed by Vannevar Bush (1890-1974) for use in the electrical engineering department at MIT. Built from 1927, the differential analyzer was a room-sized analog, mechanical computing device designed principally to integrate equations. Building on Bush's example, differential analyzers would be built in Europe as well as the United States. They required repositioning of components for each problem carried out, and proved slower and less flexible - though initially more reliable - than electronic computers.
After MIT had built improved differential anzlyzers, this one was moved to and used at Wayne University in Detroit. By 1956, it was no longer needed there, and given to the Smithsonian..
For related transaction, with other parts to the MIT differential analyzer, see 1983.3002. For a more complete differential analyzer, used at UCLA, see 1983.0023.
Reference:
Larry Owens, "Vannevar Bush and the Differential Analyzer: The Text and Context of an Early Computer," Technology and Culture, vol. 37, #1, 1986, pp. 63-95.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
MA.314824
catalog number
314824
accession number
208694
In this large open arrangement of steel shafts, one shaft is set perpendicular to another. This was the carriage for the input table. The graph of a function to be entered into the machine was placed on an input table.
Description
In this large open arrangement of steel shafts, one shaft is set perpendicular to another. This was the carriage for the input table. The graph of a function to be entered into the machine was placed on an input table. Each carriage could be moved so that the pointer on it followed the curve. It was connected to a shaft which transported the pointer's motion to the appropriate part of the machine.
For a related transaction, see 208694. Further components are also in other parts of transaction 1983.3002.
Location
Currently not on view
date made
ca 1930
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.01
catalog number
1983.3002.01
nonaccession number
1983.3002
This steel and brass component served as an adder, it connected two shafts, a and b, whose sum c = a + b was to be obtained. The adder consists of a differential gear.
Description
This steel and brass component served as an adder, it connected two shafts, a and b, whose sum c = a + b was to be obtained. The adder consists of a differential gear. The gear ratio was chosen so that the sum of the revolutions of shafts a and b would equal a revolution of shaft c.
Parts of Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.02
nonaccession number
1983.3002
catalog number
1983.3002.02
The rotation of a shaft representing results calculated by the differential analyzer were transmitted to a tracer that drew the results on an output table. This is the carriage for the tracer point, with tracer point.
Description
The rotation of a shaft representing results calculated by the differential analyzer were transmitted to a tracer that drew the results on an output table. This is the carriage for the tracer point, with tracer point. It is a large open arrangement of steel shafts, with one shaft is perpendicular to a double set.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.03
nonaccession number
1983.3002
catalog number
1983.3002.03
The steel shaft has a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum and a planetary gear train links it to a steel disc. A brass end piece fits over the shaft and has an internal gear. The end piece comes off easily.
Description
The steel shaft has a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum and a planetary gear train links it to a steel disc. A brass end piece fits over the shaft and has an internal gear. The end piece comes off easily. This frontlash unit on the Bush differential analyzer compensated for the backlash in a given drive between the output shaft of the unit and input shaft of an adjacent unit.
A mark on the disc and end piece reads: 8.
Compare to 1983.3002.09, .10 and .11.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.04
nonaccession number
1983.3002
catalog number
1983.3002.04
This steel shaft runs through a series of steel rings, each with a gear next to it. One ring is attached to one gear. Each ring has one protrusion. Seventeen rings are of one size, twenty-two of a larger size. Each ring is marked: BOSTON.
Description
This steel shaft runs through a series of steel rings, each with a gear next to it. One ring is attached to one gear. Each ring has one protrusion. Seventeen rings are of one size, twenty-two of a larger size. Each ring is marked: BOSTON. The Boston Gear Works manufactured several parts used in the Bush differential analyzer.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.05
nonaccession number
1983.3002
catalog number
1983.3002.05
Each component consists of an iron framework that holds two perpendicular, linked gears on steel shafts that pass through the framework.
Description
Each component consists of an iron framework that holds two perpendicular, linked gears on steel shafts that pass through the framework. There are two examples.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.06
nonaccession number
1983.3002
catalog number
1983.3002.06
This steel shaft carries nine components of one kind and three of a second kind on it.
Description
This steel shaft carries nine components of one kind and three of a second kind on it. All of these components have a pattern of indentations and all rotate on the shaft.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.07
nonaccession number
1983.3002
catalog number
1983.3002.07
On this steel shaft, gears in two sizes are attached to rings and lined up on the shaft as in 1983.3002.05. Some gears are marked with numbers. Some are marked: BOSTON.
Description
On this steel shaft, gears in two sizes are attached to rings and lined up on the shaft as in 1983.3002.05. Some gears are marked with numbers. Some are marked: BOSTON. the mark refers to the products of the Boston Gear Works.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.08
nonaccession number
1983.3002
catalog number
1983.3002.08
This steel shaft has a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum. The central gear train is missing. There is then a brass disc fixed to the shaft and a brass end piece that fits over the shaft and has an internal gear.
Description
This steel shaft has a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum. The central gear train is missing. There is then a brass disc fixed to the shaft and a brass end piece that fits over the shaft and has an internal gear. The disc and end piece are marked: 5. This is part of a frontlash unit.
Compare to 1983.3002.04, 1983.3002.10., and 1983,3002.11.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.09
nonaccession number
1983.3002
catalog number
1983.3002.09
This component includes a gear constrained to rotate on a shaft with the limits of its motion set by a mechanism moving inside a wheel. A mark on it reads: MADE IN U.S.A.
Description
This component includes a gear constrained to rotate on a shaft with the limits of its motion set by a mechanism moving inside a wheel. A mark on it reads: MADE IN U.S.A. N D 39 R.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.16
nonaccession number
1983.3002
catalog number
1983.3002.16
This steel shaft carries a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum and a planetary gear train links it to a steel disc. The disc is marked: 4.
Description
This steel shaft carries a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum and a planetary gear train links it to a steel disc. The disc is marked: 4. There is no endpiece.
Compare 1983.3002.04, 1983.3002.09, and 1983.3002.11.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.10
nonaccession number
1983.3002
catalog number
1983.3002.10
This steel shaft carries a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum and a planetary gear train links it to a steel disc.
Description
This steel shaft carries a steel cylinder next to a thin rotating brass drum. A friction band goes around the drum and a planetary gear train links it to a steel disc. The disc and brass end piece are marked: 2.
Compare to 1983.3002.04; 1983.3002.09; and 1983.3002.10.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.11
nonaccession number
1983.3002
catalog number
1983.3002.11
This steel shaft carries a rotating round piece that has been flattened along part of its circumference.Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.Currently not on view
Description
This steel shaft carries a rotating round piece that has been flattened along part of its circumference.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.12
nonaccession number
1983.3002
catalog number
1983.3002.12
In this component, two joined brass gears move on a steel shaft that has a bolt that screws onto one end.Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.Currently not on view
Description
In this component, two joined brass gears move on a steel shaft that has a bolt that screws onto one end.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.13
nonaccession number
1983.3002
catalog number
1983.3002.13
In this component, a metal gear is attached above a metal plate.
Description
In this component, a metal gear is attached above a metal plate. The other end of the plate supports another metal plate and is held to it by a nut and bolt.
Parts of the Bush differential analyzer at NMAH have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.14
nonaccession number
1983.3002
catalog number
1983.3002.14
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.In this component, two spiral gears are linked perpendicularly in a steel framework.Currently not on view
Description
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
In this component, two spiral gears are linked perpendicularly in a steel framework.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.15
nonaccession number
1983.3002
catalog number
1983.3002.15
This short shaft holds a gear at one end and an iron piece at the other. Both the gear and the iron piece rotate. A mark reads: BOST [. .
Description
This short shaft holds a gear at one end and an iron piece at the other. Both the gear and the iron piece rotate. A mark reads: BOST [. . .].
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.17
nonaccession number
1983.3002
catalog number
1983.3002.17
This short brass piece holds a ring that rotates on ball bearings and a gear. A mark on the gear reads: 146335 5. A mark on the ring reads: FAFNIR S [. .
Description
This short brass piece holds a ring that rotates on ball bearings and a gear. A mark on the gear reads: 146335 5. A mark on the ring reads: FAFNIR S [. . .] K USA..
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.18
nonaccession number
1983.3002
catalog number
1983.3002.18
One of these two components consists of a steel shaft that holds bolt at one end; then a gear and then cylinder that fits into another cylinder.
Description
One of these two components consists of a steel shaft that holds bolt at one end; then a gear and then cylinder that fits into another cylinder. The second component is identical excecpt that the second cylinder is missing.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.19
nonaccession number
1983.3002
catalog number
1983.3002.19
This steel gear on a steel shaft has a mechanism so that it can be set in either of two positions.Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.Currently not on view
Description
This steel gear on a steel shaft has a mechanism so that it can be set in either of two positions.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.20
nonaccession number
1983.3002
catalog number
1983.3002.20
This brass ring is set on a steel shaft in such a way that it can be rotated into various positions and then set in place with a pin.Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.Currently
Description
This brass ring is set on a steel shaft in such a way that it can be rotated into various positions and then set in place with a pin.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.21
catalog number
1983.3002.21
nonaccession number
1983.3002
Each of these two identical steel rings has four holes around the perimeter (these are not on the edge).
Description
Each of these two identical steel rings has four holes around the perimeter (these are not on the edge). There is a lip around one side.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.22
catalog number
1983.3002.22
nonaccession number
1983.3002
Each of these two components consists of a gear with cylinder on shaft.Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.Currently not on view
Description
Each of these two components consists of a gear with cylinder on shaft.
Parts of the Bush differential analyzer surviving at the Smithsonian have museum numbers MA.314824 and 1983.3002.01 through 1983.3002.89.
Location
Currently not on view
date made
ca 1930
maker
Bush, Vannevar
ID Number
1983.3002.23
catalog number
1983.3002.23
nonaccession number
1983.3002

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