#
Science & Mathematics

The Museum's collections hold thousands of objects related to chemistry, biology, physics, astronomy, and other sciences. Instruments range from early American telescopes to lasers. Rare glassware and other artifacts from the laboratory of Joseph Priestley, the discoverer of oxygen, are among the scientific treasures here. A Gilbert chemistry set of about 1937 and other objects testify to the pleasures of amateur science. Artifacts also help illuminate the social and political history of biology and the roles of women and minorities in science.

The mathematics collection holds artifacts from slide rules and flash cards to code-breaking equipment. More than 1,000 models demonstrate some of the problems and principles of mathematics, and 80 abstract paintings by illustrator and cartoonist Crockett Johnson show his visual interpretations of mathematical theorems.

"Science & Mathematics - Overview" showing 1265 items.

Page 2 of 127

## Model of a Riemann Surface by Richard P. Baker, Baker #405wn

- Description
- This geometric model was constructed by Richard P. Baker in about 1930 when he was Associate Professor of Mathematics at the University of Iowa. Baker believed that models were essential for the teaching of many parts of mathematics and physics, and over one hundred of his models are in the museum collections.

- The mark "405 w" is carved into one edge of the wooden base of this model and the typed part of a paper label on the base reads: No. 405 zn (/) Riemann surface : w
^{2}= z^{3}- z. The label should have read "405 wn" and someone added a handwritten question mark after the "zn." Model 405wn is listed on page 17 of Baker’s 1931 catalog of models as “w^{2}= z^{3}- z” under the heading*Riemann Surfaces*. This means that the model represents a Riemann surface consisting of pairs of complex numbers, (z,w), for which w^{2}= z^{3}- z. Complex numbers are of the form x + yi for x and y real numbers and i the square root of –1. The spheres of the model are called complex, or Riemann, spheres. They are formed with north and south poles representing ∞ and 0, respectively. The equator represents the points x + yi with x^{2}+ y^{2}= 1. Thus the points ±1 and ±i are equally spaced along the equator. Riemann surfaces and spheres are named after the 19th-century German mathematician Bernhard Riemann.

- Baker explains in his catalog that the wn after the number of the model indicates that the model is made up of spheres representing w-values. These spheres are called the sheets of the model. There is no part of this model in which values of z or pairs (z,w) are represented. However, it is possible that the coloring on this model is related to the painted part of the wooden base of one of three other Baker models of Riemann surfaces that are associated with the equation of this model.

- If w = ±
^{4}√ (4/27) or w = ±i^{4}√ (4/27), the equation w^{2}= z^{3}- z is satisfied by two distinct values of z. For the two real values of w, ±^{4}√ (4/27), z takes the values –1/√3 and 2/√3, and for the two imaginary values of w, ±i^{4}√ (4/27), z takes the values 1/√3 and –2/√3. These four points together with the point z = ∞ are called branch points of the model and for all other points on the w-sphere the equation w^{2}= z^{3}- z is satisfied by three distinct values of z, each of which produces a different pair on the Riemann surface (if w = 0, the three distinct pairs on the Riemann surface are (0,0) and (±1,0)). Thus there are three sheets representing the complex w-sphere and together they represent what is called a branched cover of the complex w-sphere.

- On each of the sheets the equator is a thin circle and there are two great circles through the poles. On one of the great circles the values of w are purely imaginary while on the other they are real. Baker’s usual use of colors implies that the great circles facing the front and back represent imaginary numbers, while those facing the sides represent real numbers. Normally w = ∞ is at the north pole and w = 0 is at the south pole. However, as the four finite branch points of this model lie in the northern hemisphere, it appears that this model has that assignment of values reversed. The great circle facing the front and back has a thick white segment that connects the two imaginary branch points by way of w = ∞ at the south pole, while the other has a thick black segment connecting the two real branch points by way of w = 0 at the north pole. The parts of the great circles that connect two branch points are called branch cuts. This model has three, one is the black arc mentioned above and the others are the two halves of the white arc with ends at an imaginary branch point and infinity. These branch cuts are curves on a sheet that produce movement to another sheet. This movement occurs when meeting a branch cut while following a path of the inputs of w values into the equation.

- There are three other models of Riemann surfaces in the collections that are associated with the equation of this model. One, a model with Baker’s no. 405w (MA*211257.068), has “405w” carved on the base Two others, Baker’s no. 405z (MA*211257.070) and Baker’s no. 405zn (MA*211257.071), both have the mark “405z“ carved on them. Baker carved a "w" or a "z" to indicate which variable is represented on the sheets of the model and added an "n" after the "w" or "z" to indicate that the sheets of the model are spheres.

- Location
- Currently not on view

- date made
- ca 1915-1935

- maker
- Baker, Richard P.

- ID Number
- MA*211257.069

- accession number
- 211257

- catalog number
- 211257.069

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Model of a Riemann Surface by Richard P. Baker, Baker #405z

- Description
- This geometric model was constructed by Richard P. Baker in about 1930 when he was Associate Professor of Mathematics at the University of Iowa. Baker believed that models were essential for the teaching of many parts of mathematics and physics, and over one hundred of his models are in the museum collections.

- The mark 405 z is carved into one edge of the wooden base of this model and the typed part of a paper label on the base reads: No. 405 w (/) Riemann surface : w
^{2}= z^{3}- z. Someone corrected the error on the label by hand, crossing out the w and inserting a z. Model 405z is listed on page 17 of Baker’s 1931 catalogue of models as “w^{2}= z^{3}- z” under the heading*Riemann Surfaces*. This means that the model represents a Riemann surface consisting of pairs of complex numbers, (z,w), for which w^{2}= z^{3}- z. Complex numbers are of the form x + yi for x and y real numbers and i the square root of –1. A complex plane is like the usual real Cartesian plane but with the horizontal axis representing the real part of the number and the vertical axis representing the imaginary part of the number. Riemann surfaces are named after the 19th-century German mathematician Bernhard Riemann.

- Baker explains in his catalogue that the z after the number of the model indicates that the metal disks above the wooden base represent copies of a disk in the complex z-plane. These disks are called the sheets of the model. The painted part of the wooden base of the model represents a square in the complex w-plane with the point w = 0 at its center and the real axis along the line between the yellow and dark green stripes.

- If z = 0 or z = ±1, the equation w
^{2}= z^{3}- z is satisfied by only one value of w, i.e., w = 0. These three points on the z-plane are called branch points of the model and for all other points on the z-plane the equation w^{2}= z^{3}- z is satisfied by two distinct values of w, each of which produces a different pair on the Riemann surface (if z = 2, the two distinct pairs on the Riemann surface are (2, ±√6)). Thus there are two sheets representing the same disk in the complex z-plane and together they represent part of what is called a branched cover of the complex z-plane. The color of a region on a sheet is chosen with the aim of indicating the stripe on the base in which the w coordinate lies.

- For each sheet, the center of the disc is the point z = 0 and the solid black line through that point is the real axis. The branch points of this model all lie on the real axis. The point z = –1 is the point inside the green and yellow oval where the real axis meets the small red circle representing the unit circle with center z = 0. The point z = 1 is the other point where the real axis meets the small red circle; it is inside the oval that includes all eight colors used in the model.

- The vertical surfaces between the two sheets are not part of the Riemann surface but call attention to what are called branch cuts of the model, i.e., curves on a sheet that produce movement to another sheet. This movement occurs when meeting a branch cut while following a path of the inputs of z values into the equation. While the defining equation determines the branch points, the branch cuts are not fixed by the equation but, normally, each branch cut goes through two of the surface’s branch points or runs out to infinity. In this model, one of the branch cuts connects z = 0 to z = 1 and the other runs from z = –1 to infinity; they are represented by the horizontal edges of the vertical surfaces.

- There are three other models of Riemann surfaces in the collections that are associated with the equation of this model. One, a model with Baker's number 405zn (MA*211257.071), has "405z" carved on the base. Two others, one with Baker's number 405w (MA*211257.068) and the other with Baker's number 405wn (MA*211257.069) have "405w" carved on the edge of the base. Baker carved a "z" or a "w" to indicate which variable is represented on the sheets of the model and added an "n" after the "z" or "w" to indicate that the sheets of the model are spheres.

- Location
- Currently not on view

- date made
- ca 1915-1935

- maker
- Baker, Richard P.

- ID Number
- MA*211257.070

- accession number
- 211257

- catalog number
- 211257.070

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Model of a Riemann Surface by Richard P. Baker, Baker #405zn

- Description
- This geometric model was constructed by Richard P. Baker in about 1930 when he was Associate Professor of Mathematics at the University of Iowa. Baker believed that models were essential for the teaching of many parts of mathematics and physics, and over one hundred of his models are in the museum collections.

- The mark "405 z" is carved into one edge of the wooden base of this model and the typed part of a paper label on the base reads: No. 405 wn (/) Riemann surface : w
^{2}= z^{3}- z. The label is incorrect and should read "405 zn". Model 405zn is listed on page 17 of Baker’s 1931 catalogue of models as “w^{2}= z^{3}- z” under the heading*Riemann Surfaces*. This means that the model represents a Riemann surface consisting of pairs of complex numbers, (z,w), for which w^{2}= z^{3}- z. Complex numbers are of the form x + yi for x and y real numbers and i the square root of –1. The spheres of the model are called complex, or Riemann, spheres. They are formed with north and south poles representing ∞ and 0, respectively. The equator represents the points x + yi with x^{2 + y}2 = 1. Thus the points ±1 and ±i are equally spaced along the equator. Riemann surfaces and spheres are named after the 19th-century German mathematician Bernhard Riemann.

- Baker explains in his catalog that the zn after the number of the model indicates that the model is made up of spheres representing z-values. These spheres are called the sheets of the model. It appears as if painted part of the wooden base of the model represents the Riemann surface as a torus, i.e., a donut, formed by pasting together the ends of the stripes to form a cylinder and then joining the ends of the cylinder.

- If z = 0 or z = ±1, the equation w
^{2}= z^{3}- z is satisfied by only one value of w, i.e., w = 0. These three points together with the point z = ∞ are called branch points of the model and for all other points on the z-sphere the equation w^{2}= z^{3}- z is satisfied by two distinct values of w, each of which produces a different pair on the Riemann surface (if z = 2, the two distinct pairs on the Riemann surface are (2, ±√6)). Thus there are two sheets representing the complex z-sphere and together they represent what is called a branched cover of the complex z-sphere. The color of a region on a sheet is chosen with the aim of indicating the stripe on the base into which it is mapped.

- On each of the sheets the equator is colored red and there are great circles through the poles that are colored yellow and black. The points on the yellow great circle are purely imaginary while those on the black great circle are real. Thus the real non-zero branch points, z = ±1, lie on the equator and on the black great circle, while the other two branch points are at the north and south poles. The darkened parts of the black great circle are called branch cuts. Assuming the pair (1,0) lies on the Riemann surface along edge shared by the center (yellow and green) stripes on the base and that the pair (–1,0) lies along the edges of the outer stripes on the base, one of the branch cuts runs between join z = 0 and z = 1 and other between z = –1 and z = ∞. These branch cuts are curves on a sheet that produce movement to another sheet. This movement occurs when meeting a branch cut while following a path of the inputs of z values into the equation. Thus one can construct the Riemann surface as a torus by cutting the spheres along the branch cut and sewing the two spheres together along those cuts while matching the four branch points.

- There are three other models of Riemann surfaces in the collections that are associated with the equation of this model. One, with Baker's number 405z (MA*211257.070) has "405z" carved on the base. Two others, Baker's number 405 w (MA*211257.068) and Baker's number 405wn (MA*211257.069) have the mark "405w" on the base. Baker carved a "z" or a "w" to indicate which variable is represented on the sheets of the model and added an "n" after the "z" or "w" to indicate that the sheets of the model are spheres.

- Location
- Currently not on view

- date made
- ca 1915-1935

- maker
- Baker, Richard P.

- ID Number
- MA*211257.071

- accession number
- 211257

- catalog number
- 211257.071

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Geometric Model by A. Harry Wheeler, One-Sided Polyhedron

- Description
- In the late 1930s and early 1940s, A. Harry Wheeler took great interest in polyhedra with interpenetrating sides, such as had been discussed by the German mathematician August F. Moebius. In this example, each of the two like-colored quadrilaterals (e.g. the two yellow sides) on the top pass through the model and appear as a white quadrilateral on the bottom. These three figures thus contribute only one side to the polygon.

- A mark on the model reads: 695. This was Wheeler’s number for the model. Models MA*304723.413, MA*304723.397, and MA*304723.398 fit together. Model MA*304723.409 is a compound of four models like MA*304723.413.

- Reference:

- Kurt Reinhardt, “Zu Moebius’ Polyhedertheorie,”
*Berichte über die Verhandlungen der Königlich Sächsischen Gesellschaft der Wissenschaften zu Leipzig. Mathematisch-Physische Classe*, 37, pp. 106-125. Wheeler referred to this article.

- Location
- Currently not on view

- date made
- ca 1940

- maker
- Wheeler, Albert Harry

- ID Number
- MA*304723.413

- accession number
- 304723

- catalog number
- 304723.413

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Rutherfurd Photograph of the Moon

- Description
- Lewis M. Rutherfurd built an observatory in the garden of his house in lower Manhattan in 1856, and installed a refracting telescope achromatized for the photographic rays. He took this remarkable lunar image in March 1865, three days after first quarter, and sent copies to astronomers in the United States and abroad.

- This example came from Princeton University. It is marked "Lewis M. Rutherfurd" and "N. Y. March 6, 1865." It measures 23⅞ inches high x 17½ inches wide.

- Ref: D. J. Warner, "Lewis M. Rutherfurd: Pioneer Astronomical Photographer and Spectroscopist,"
*Technology and Culture*12 (1971): 190-216.

- Location
- Currently not on view

- date made
- 1865

- maker
- Rutherfurd, Lewis Morris

- ID Number
- PH*328883

- catalog number
- 328883

- accession number
- 277637

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Rutherfurd Diffraction Grating

- Description
- This is one of the earliest gratings made by Lewis M. Rutherfurd, and one of three that the pioneer astrophysicist, Henry Draper, acquired in the fall of 1872. The glass plate measures 1⅜ inches square and is marked "Nov. 19, 1872, 6480 per inch L. M. Rutherfurd."

- Ref. D. J. Warner, "Lewis M. Rutherfurd: Pioneer Astronomical Photographer and Spectroscopist,"
*Technology and Culture*12 (1971): 190-216.

- Location
- Currently not on view

- date made
- 1872

- maker
- Rutherfurd, Lewis Morris

- ID Number
- PH*334273

- accession number
- 304826

- catalog number
- 334273

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Agassiz, Peirce, and Patterson

- Description
- Benjamin Peirce, Harvard professor of mathematics and third superintendent of the U.S. Coast Survey, was on good terms with Louis Agassiz, the charismatic Swiss naturalist who taught at Harvard’s Lawrence Scientific School and served as the founding director of Harvard’s Museum of Comparative Zoology. Writing to Agassiz in February 1871, Peirce announced that the Coast Survey was about “to send a new iron steamer round to California” and asked if Agassiz would “go in her, and do deep-sea dredging all the way around?” Since Agassiz had conducted several research projects under the aegis of the Coast Survey, Peirce expected that he would accept this new proposition. The new ship, the first iron-hulled vessel owned by the Survey, was designed to dredge at depths never before reached. Named the
*Hassler*after the first superintendent of the Coast Survey, the ship's maiden voyage would be known as the Hassler Expedition.

- The Coast Survey had the largest budget of any 19th-century American scientific organization, and employed more scientists, both directly and indirectly. But aware of Congressional concerns about how federal funds should be spent, the Survey tended to hide its science behind its more practical activities. Thus while the
*Hassler*sailed from the East Coast where it was built to the Pacific Coast where it would see service, the ship` could transport Agassiz, his wife, and several colleagues and assistants. But Agassiz had to raise the $20,000 needed to preserve the many specimens they hoped to collect and send back to the States for further study. Most of these specimens went to the Museum of Comparative Zoology and the Smithsonian Institution.

- The Hassler left the Boston Navy Yard on Dec. 4, 1871 and made land in San Francisco some nine months later. Despite equipment failure and various delays, much was accomplished on the Expedition. The Coast Survey aimed to discover the origin of the Gulf Stream, determine the greatest depth of the Atlantic, exploring the coasts of Patagonia, chart the dangerous currents in and around the Straits of Magellan, and trace Darwin’s steps in the Galapagos Islands. Agassiz was especially interested in evidence of glacial action in the Southern Hemisphere (which he found), and evidence that might disprove Darwin’s theory of evolution (which he did not).

- The
*Hassler*left the Boston Navy Yard on Dec. 4, 1871 and made land in San Francisco some nine months later. Despite equipment failure and various delays, much was accomplished on the expedition. The Coast Survey aimed to discover the origin of the Gulf Stream, determine the greatest depth of the Atlantic, explore the coasts of Patagonia, chart the dangerous currents in and around the Straits of Magellan, and trace Darwin’s steps in the Galapagos Islands. Agassiz was especially interested in evidence of glacial action in the Southern Hemisphere (which he found), and evidence that might disprove Darwin’s theory of evolution (which he did not).

- This large, carefully posed and somewhat manipulated photograph was made while plans for the expedition were underway. Agassiz is seated at the left of a round table, Peirce stands behind the table, and Carlile Patterson, the Hydrographic Inspector of the Coast Survey (and the man who had planned the internal arrangements of the new ship) sits at right. These men seem to be discussing a chart attached to which an obviously enlarged piece of paper carries the hand-written inscription “Instructions for Expd.” and “To. Prof. L. Agassiz / from Captain C. Patterson / Yours respectfully / Benjamin Peirce / Superintendent.”

- The text at bottom of the photograph reads “Entered according to Act of Congress in the year 1871 by A. SONREL, in the Office of the Librarian of Congress at Washington, D.C.” This refers to the federal copyright act of 1870. That image is now in the Prints and Photographs Division of the Library of Congress. It is identical to our copy, but has an “A. Sonrel” signature in the lower left.

- Antoine Sonrel (d. 1879) was an accomplished scientific illustrator who had worked with Agassiz in Neuchâtel, followed him to the United States, and prepared the lithographic plates for several of his publications. He was also an accomplished photographer who did commercial and scientific work. Several Agassiz cartes-de-visite photographs were taken by in Sonrel’s Boston studio. Another Sonrel photograph dated 1871, probably taken on the same day as our image, shows Agassiz and Peirce, the former seated in a chair, and the latter standing with his right hand on a globe pointing to Boston. And, as our image indicates, Sonrel, like many photographers then as now, enjoyed manipulating images. Another Sonrel photograph shows Agassiz talking to Agassiz across a table. Yet another shows an unidentified man playing chess with himself.

- According to a note on the back of the frame, this photograph was purchased at an auction of the effects Mrs. John Cummings in 1928. The reference is to Mary Phelps Cowles (1839-1927), a woman of culture and wealth who was married to Adino Brackett Hall, a Boston physician, and then John Cummings, a landowner in Woburn, Ma.

- Ref: Christoph Irmscher,
*Louis Agassiz. Creator of American Science*(Boston, 2013).

- David Dobbs,
*Reef Madness: Charles Darwin, Alexander Agassiz, and the Meaning of Coral*(New York, 2005).

- Edward Hogan,
*Of the Human Heart. A Biography of Benjamin Peirce*(Bethlehem, 2008), pp. 270-280.

- Location
- Currently not on view

- date made
- 1871

- depicted (sitter)
- Agassiz, Louis

- ID Number
- 1990.0326.01

- catalog number
- 1990.0326.01

- accession number
- 1990.0326

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Omicron Ellipsograph

- Description
- The Omicron Ellipsograph Model 17 was manufactured by the Omicron Company of Glendale, CA, in the 1950s. An oval shape, the ellipse is one of the four conic sections, the others being the circle, the parabola, and the hyperbola. Ellipses are important curves used in the mathematical sciences. For example, the planets follow elliptical orbits around the sun. Ellipses are required in surveying, engineering, architectural, and machine drawings for two main reasons. First, any circle viewed at an angle will appear to be an ellipse. Second, ellipses were common architectural elements, often used in ceilings, staircases, and windows, and needed to be rendered accurately in drawings. Several types of drawing devices that produce ellipses, called ellipsographs or elliptographs, were developed and patented in the late 19th and early 20th centuries. The U.S. Army purchased several examples of this device for use in surveying and mapping.

- The Omicron Ellipsograph is not an elliptic trammel like many of the other ellipsographs in the Smithsonian’s collections. This ellipsograph is a linkage, in particular a Stephenson type III linkage. A linkage is a mechanical device made of rigid bars connected by hinges or pivot points that move in such a way as to produce smooth mathematical curves. The most common types of linkages are used to draw true straight lines. See the Kinematic Models in the Smithsonian’s online collections for examples of other linkages.

- In this ellipsograph, a metal bar is attached to two sliding brackets. One is on the stationary bar that runs horizontally across the device and is the major axis of the ellipse. The other sliding bracket is attached to a curved arm. A pencil is inserted through the hole at the top end of the bar. As the pencil is moved, the linkage articulates at five pivot points (the two adjustable sliders and three pivots as seen in the image). This constrains the pencil to move in an elliptic arc. Unlike the elliptic trammel, only half an ellipse can be drawn with this device, making it a semi-elliptic trammel. It can be turned 180 degrees to draw the other half of the ellipse. Although this device cannot draw a complete ellipse in one motion, it does have the advantage of being able to draw very small ellipses. By adjusting the distance between the two slider brackets, the eccentricity of the ellipse can be changed. Eccentricity is a number between zero and one that describes how circular an ellipse is. By moving the slider brackets closer together, the eccentricity of the ellipse is reduced, creating a more circular ellipse. As the brackets are moved farther apart, the eccentricity is increased and a more elongated ellipse is produced.

- Several demonstrations of how an elliptic trammel works are available online. Comparing the slider motion of the elliptical trammel and the linkage ellipsograph highlights the similarities of the motion of these two ellipsographs. Both devices constrain the motion of the sliders so that as one moves inward on a straight line, the other slider moves outward on a straight line perpendicular to the first. Thus both types of ellipsographs produce an elliptic curve using the same mathematical theory, but incorporating different physical configurations.

- The Omicron Ellipsograph is made of aluminium and steel on an acrylic base. The base is 18.5 cm by 8.5 cm (7 1/4 in by 3 3/8 in). The top bar is 18 cm (7 in) long. The whole linkage rests on the central pivot directly above the company logo. It can draw ellipses with major axes up to 12 inches long.

- Resources:

*Antique Drawing Instrument Collection*, http://collectingme.com/drawing/.

- John Byant, Chris Sangwin,
*How Round is Your Circle?: Where Engineering and Mathematics Meet*, Princeton: Princeton University Press, 2008, p. 290.

- Location
- Currently not on view

- date made
- ca 1954

- maker
- Omicron

- ID Number
- 1987.0379.02

- accession number
- 1987.0379

- catalog number
- 1987.0379.02

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Friden Model SBT 10 Calculating Machine

- Description
- This modification of Friden’s fully automatic STW calculating machine allows for “back transfer.” That is to say, it has a mechanism to transfer figures from the accumulator register to the keyboard selecting levers and vice versa. The model was manufactured from 1959 until 1965.

- The full-keyboard electric non-printing stepped drum machine has a metal frame painted tan and ten columns of brown and white plastic keys, with a blank white key at the bottom of each column. Metal rods between the columns of keys and under the keyboard turn to indicate decimal points. On the right are two columns of function bars. On the left is a nine-digit register that indicates numbers entered for multiplication. Below it is a block of nine white digit keys, with a 0 bar below. These are surrounded by further levers and function keys, including a split “NEG POS TRANSFER” bar.

- Behind the entry keys is a movable carriage with an 11-digit register and a 20-digit result register. The result register has plastic buttons above it that can be used to set up numbers. Nine entry buttons and a clear button are under the revolution register. Zeroing knobs for the registers are on the right of the carriage. A clear carriage bar is toward the front of the keyboard. All three registers have sliding decimal markers. The machine has four hard rubber feet as well as a rubber cord and a tan plastic cover.

- A mark on the bottom reads: MODEL SERIAL (/) SBT 10 907698. A mark on the back and side reads: Friden. A sticker on the bottom reads: FRIDEN, INC. (/) SAN LEONARDO, CALIFORNIA, USA. A mark on the cover reads: Friden (/) AUTOMATIC CALCULATOR.

- For related documents, see 1984.0475.02, 1984.0475.03, 1984.0475.07, and non-accession 1984.3079.

- This is one of five Friden calculating machines given to the Smithsonian by Vincent L. Corrado (1917-1984), a native of Covington, Kentucky, who earned bachelor’s and master’s degrees in accounting at Catholic University, served in the U.S. Army from 1942 through 1973, and then joined the Veteran’s Administration for the rest of his life.

- The date given is based on the serial number, courtesy of Carl Holm. This is the date of manufacture.

- Reference:

- Ernie Jorgenson,
*Friden Age List*, Office Machine Americana, p. 5 gives the date 1960 for this machine.

- Location
- Currently not on view

- date made
- 1964

- maker
- Friden, Inc.

- ID Number
- 1983.0475.01

- catalog number
- 1983.0475.01

- accession number
- 1983.0475

- maker number
- SBT 10 907698

- Data Source
- National Museum of American History, Kenneth E. Behring Center

## Biolistic Gene Transfer Process Shadow Box

- Description (Brief)
- This shadow box display demonstrates the biolistic gene transfer process, the firing mechanism of the gene gun. The object came from the offices of Biolistics Inc., a company started in 1988 by Dr. Ed Wolf and Dr. John Sanford in Ithaca, New York, to sell their biolistic gene guns. Biolistic gene guns are used to genetically transform plants by shooting microprojectiles (tiny bullets) covered in DNA into plant cells. It’s likely that this shadow box was used to help explain the firing process to potential investors or purchasers of the technology.

- The firing mechanism of the gene gun required several steps, as shown here. A gunpowder charge (see object 1991.0785.03.2) or compressed air was used to accelerate a macroprojectile (see object 1991.0785.03.3), upon whose tip rested DNA-coated microprojectiles. The macroprojectile would be halted upon its impact with a stopping plate (see object 1991.0785.03.4). The stopping plate is the first large plastic disk shown here. A hole in the stopping plate was small enough to allow the microprojectiles to pass through, but large enough to halt the macroprojectile.

- The second plastic disk shown here is an example of a fused stopping plate and macroprojectile (see object 1991.0785.03.5). The microparticles then continued to move forward, eventually penetrating the cells to be transformed. The triangular black shape represents the microparticles continuing forward after they have gone through the stopping plate. Cells to be transformed are represented by the round plastic beads.

- To learn more about biolistic gene guns, please see gene gun prototype II (object number 1991.0785.02) or gene gun prototype III (object number 1991.0785.01.1).

- Location
- Currently not on view

- ID Number
- 1992.0023.01

- catalog number
- 1992.0023.01

- accession number
- 1992.0023

- Data Source
- National Museum of American History, Kenneth E. Behring Center