#
Engineering, Building, and Architecture

Not many museums collect houses. The National Museum of American History has four, as well as two outbuildings, 11 rooms, an elevator, many building components, and some architectural elements from the White House. Drafting manuals are supplemented by many prints of buildings and other architectural subjects. The breadth of the museum's collections adds some surprising objects to these holdings, such as fans, purses, handkerchiefs, T-shirts, and other objects bearing images of buildings.

The engineering artifacts document the history of civil and mechanical engineering in the United States. So far, the Museum has declined to collect dams, skyscrapers, and bridges, but these and other important engineering achievements are preserved through blueprints, drawings, models, photographs, sketches, paintings, technical reports, and field notes.

"Engineering, Building, and Architecture - Overview" showing 1231 items.

Page 4 of 124

## Time-O-Stat, 8 Day Jeweled Thermostat

- Description
- This Time-O-Stat 8-Day Thermostat was manufactured by the Time-O-Stat Controls Corporation of Elkhart, Indiana around 1932. The home owner could program thermostat to keep different temperatures during the day or night, and the clock switched between these temperatures for 8 days before it needed to be wound. The thermostat’s temperature could be set between 60 and 80, and the thermometer on the front displays the temperature from 30 to 100 degrees. This thermostat contained a mercury switch on a helical bi-metal coil, the mercury served to slow the opening and closing of the circuit that controlled the furnace, preventing “short-cycling.” Time-O-Stat was a large company that specialized in control systems that had applications in a variety of industrial, commercial, and domestic applications. Time-O-Stat was purchased by the Minneapolis-Honeywell Regulator Company in 1934, who continued to sell a Time-O-Stat brand thermostat in the years following the acquisition and used Time-O-Stat control patents in future devices.

- The ubiquity of thermostats in 21st century homes shrouds the decades of innovation, industrial design, and engineering that went into making them an everyday object in almost every home. In the early 20th century, a majority of American households still heated their homes with manually operated furnaces that required a trip down to the basement and stoking the coal fired furnace. Albert Butz’s “damper-flapper” system was patented in 1886 and allowed user to set the thermostat to a certain temperature which would open a damper to the furnace, increasing the fire and heating the house. Progressive innovations allowed for the thermostats to use gas lines, incorporate electricity, turn on at a set time, include heating and cooling in one mechanism, and even connect to the internet.

- ID Number
- 2008.0011.22

- accession number
- 2008.0011

- catalog number
- 2008.0011.22

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

## Howe’s Patent Model of a Pin Making Machine - ca 1841

- Description
- This model was filed with the application to the U.S. Patent Office for Patent Number 2,013 issued to John Ireland Howe on March 24, 1841. Howe’s invention was a design for an automated common pin making machine. The goal of the design was to improve upon his earlier patented pin making machine which had not found commercial success. His design was mechanically very complex; the patent document comprised 20 pages of detailed text and five of diagrams. Howe had been a physician working in the New York Alms House where he had observed the inmates making pins by hand. He began to experiment with machinery for automating the process and sought the help of Robert Hoe, a printing press builder, to provide mechanical expertise. His design was for a machine that would take a roll of wire, cut the wire for each pin to proper length, sharpen and polish the pointed end of the pin, and finally form the other end into a metal head. The machine consisted of a series of individual chucks (devices much like on lathes) mounted radially on a vertical shaft that rotated inside a horizontal circular frame. Around the circumference of the frame were mounted various tools that shaped the pins. As the vertical shaft rotated, it brought the chucks into alignment with the tools. One type of tool was the point forming file, or mill. The chuck, which was rotating along the axis of the pin, would make the pin tip contact the file thus grinding it into shape. The file was also rotating as well as moving forward, backwards, and side-to-side in a complex manner so as to produce a point which was round, smooth, free from angles, and slightly convex in shape. Howe made provisions for multiple such tools to progressively shape the point. The other major tool was the head forming mechanism. A carrier removed the pin from its chuck and inserted its blunt end into a set of gripping jaws that held it into a set of dies. The dies formed a thickened section of metal at the end of the pin. A second carrier extracted the pin and inserted the thickened section into a second set of dies which then flattened and formed the final pin head. The machines made from the patent design enabled the Howe Manufacturing Company become one of the largest pin manufacturers in the United States.

- The patent model is constructed primary of metal and is about one foot square and one foot tall. It represents the essential elements of the design such as the rotating set of chucks mounted on the vertical shaft, the sharpening mills, and the head making mechanisms. It shows how the rotating table brings the pins to the point sharpening mills. While it is uncertain that the model would be capable of actual pin production, it appears that turning the attached hand crank would cause the machine to go through the motions of actual pin production.

- date made
- ca 1841

- patent date
- 1841-03-24

- inventor
- Howe, John I.

- ID Number
- MC*308788

- catalog number
- 308788

- accession number
- 89797

- patent number
- 2,013

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

## Ford-based Track Roadster

- Description
- Hot rods first appeared in southern California in the late 1930s and became popular in many other places after World War II. Oval track racing combined speed and spectator enjoyment. Dick Fraizer, Floyd Johnson, and Hack Winniger built this competition track roadster in Muncie, Indiana. It has a 1927 Ford Model T body, a 1928 Chevrolet chassis, and a Ford V-8 engine. Fraizer set a one-lap speed record of 84.23 miles per hour with this car at the Winchester Speedway in Indiana. It also ran at Soldiers Field in Chicago with Andy Granatelli’s Hurricane Racing Association and on tracks as far east as Virginia.

- Location
- Currently not on view

- date made
- 1948

- maker
- Anderson, Donald

- ID Number
- 1992.0028.01

- accession number
- 1992.0028

- catalog number
- 1992.0028.01

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

## Racing Go-Kart

- Description
- A truly "grass roots" sport, organized "go-karting" arose in the late 1950s. In the 1930s and late 1940s, various types of smaller open-wheeled race cars had been developed for certain classes of organized racing on oval tracks, including the "midget racers" - diminutive but full-fledged, single-seat, high-speed cars. But for would-be racers of limited means in the 1950s, even these midget race cars were out of financial reach. Meanwhile, marketers of leisure-time products had started producing small, motorized "karts" for pre-teens. Such a kart, intended for driving on paved surfaces off the public roadways, had a light frame made of tubular steel, no "body" at all, a rudimentary open seat, and was equipped with a small gasoline engine mounted behind the driver and tiny tires. Adults thought up the idea of installing more-powerful motors, and the racing "go-kart" was born. Racing of such karts by kids was soon organized -- but racing classes for adults were created as well. Such races were sometimes held at regular paved race tracks but were usually run on specialized, short paved courses designed and built expressly for the karts. In the early days, races ran on large parking lots, with courses marked off for the day with stripes and rubber cones.

- Many racing drivers who became well known in the 1970s, '80s, and through the present -- such as NASCAR's Jeff Gordon, 'Indy 500' drivers Al Unser, Jr. and Michael Andretti, and European 'Formula-1' drivers -- learned their early skills by becoming champion kart drivers in the classes for pre-teens.

- Elwood "Pappy" Hampton (1909-1980), however, was one of thousands who took to the sport as adults. He was a Washington, DC, machinist who became interested in go-kart racing as a hobby. He built several karts, each time refining their design and improving their performance.

- This kart is one made about 1960, which Hampton raced frequently from 1960 through 1962 to first-, second-, and third-place finishes, mostly at the Marlboro Speedway in Maryland. In 1962, he won the East Coast Championship. At age 51 in 1960, "Pappy" was one of the oldest successful kart racers in the mid-Atlantic area, hence his nickname.

- The kart has a duralumin chassis (duralumin for strength with extreme lightness) made especially for racing karts by Jim Rathmann of Indianapolis (the winning driver in the 1960 Indianapolis 500), and a drive train engineered and made by Hampton. The engine is one made in England, fueled on alcohol.

- Location
- Currently not on view

- date made
- ca 1960

- maker
- Hampton, Sr., Elwood N. "Pappy"

- Rathmann, James

- ID Number
- 1997.0378.01

- accession number
- 1997.0378

- catalog number
- 1997.0378.01

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

## Epitrochoid, Kinematic Model by Martin Schilling, series 24, model 1, number 329

- Description
- Around 1900, American mathematicians introduced ideas to their students using physical models like this one. This model is the first in a series of kinematic models sold by the German firm of Schilling to show a mechanical method for generating mathematical curves.

- Circles rolling around the outside of other circles, known as epicycles to the ancient Greeks, were used to describe the motions of the planets in a geocentric cosmology. These curves,called epitrochoids, are formed by tracing a point on the radius or the extension of the radius of a circle as it rolls around the outside of a second stationary circle.

- Epitrochoids are members of the family of curves called trochoids, curves that are generated by tracing the motion of a point on the radius of a circle as it rolls along another curve. They include the cycloids (see item 1982.0795.05) and hypotrochoids (see items 1982.0795.02 and 1982.0795.03). In the 18th century, it was found that when shaping the sides of gear teeth as the valley between teeth, using trochoidal curves reduced the torque of the rotating gears and allowed them to rotate more efficiently.

- Depending on the distance of the tracing point from the center of the rolling circle, an infinite number of curves can be formed. The three curves depicted in this model are bicyclic, meaning the smaller circle needs to rotate around the larger circle twice before returning to is original configuration. The ratio of the radii of the two circles will determine the number of nodes in the curve and how many rotations are required before the tracing point returns to its starting configuration. The Spirograph toy produces various types of epitrochoids. (See item 2005.0055.02)

- In this model, a toothed metal disc of radius 30 mm links to a smaller toothed metal disc of radius 12mm. Rotating a crank beneath the baseplate rolls the smaller disc around the outer edge of the larger disk. The model illustrates three curves that may be generated by the motion of a point at a fixed distance along the radius of a circle when the circle rolls around the outer edge of a larger circle.

- The green point within the smaller circle (at radius 4mm) produces the green curve on the glass overlay of the model. The blue point on the circumference of the smaller circle (in this special case, the curve is known as an epicycloid) produces the blue curve. The third, represented by a red curve on the glass, is on the extension of a radius of the smaller circle (20mm). As the smaller circle rolls, the point moves inside the larger circle. The German title of this model is: Erzeugung der Epitrochoiden als solche mit freiem Centrum.

- References:

- Schilling, Martin,
*Catalog Mathematischer Modelle für den höheren mathatischen Unterricht*, Halle a.s., Germany, 1911, pp 56-57. Series 24, group 1, model 1.

- Chironis, Nicholas,
*Gear Design and Applications*, 1967, p. 160.

- Davis, W.O.,
*Gears for Small Machines*, 1953, p. 9.

- Grant, George,
*Teeth of Gears*, 1891, p. 69.

- Material for educators can be found online at the Durango Bill website.

- Online demonstrations can be found at the Wolfram website Mathworld.

- Location
- Currently not on view

- date made
- ca 1900

- maker
- Schilling, Martin

- ID Number
- 1982.0795.01

- catalog number
- 1982.0795.01

- accession number
- 1982.0795

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

## Hypotrochoids, Kinematic Model by Martin Schilling, series 24, model 3, number 331

- Description
- Around 1900, American mathematicians introduced ideas to their students using physical models like this one. This model is the third in a series of kinematic models sold by the German firm of Schilling to show a mechanical method for generating mathematical curves.

- The name hypotrochoid comes from the Greek word hypo, which means under, and the Latin word trochus, which means hoop. Thus hypotrochoids are curves formed by tracing a point on the radius or extension of the radius of a circle rolling around the inside of another stationary circle.

- Hypotochoids are members of the family of curves called trochoids, curves that are generated by tracing the motion of a point on the radius of a circle as it rolls along another curve. They include the cycloids (see item 1982.0795.05) and epitrochoids (see item 1982.0795.01).

- An infinite number of hypotrochoids can be formed, depending on the distance of the tracing point from the center of the rolling circle. The ratio of the radius of the rolling disc to the radius of the outer ring will determine the number of nodes the hypotochoid will have. In this model, the curves each have five nodes. Hypotochoids, for which the tracing point is on the extension of the radius, form curves that resemble petalled flowers and are called roses. The Spirograph toy produces various types of hypotrochoids. (See item 2005.0055.2) In the 18th century, it was found that shaping the sides of gear teeth and the valley between teeth by using trochoidal curves reduced the torque of the rotating gears and allowed them to rotate more efficiently.

- This model consists of a stationary toothed metal ring (with teeth on the inner edge of the ring) of radius 80 mm. A toothed metal disc of radius 32 mm is attached to a brass arm of 7 cm that can be rotated by turning a crank below the baseplate. As the arm is rotated, the disc rolls around the inside of the ring. Three points lie along the radius of the disk and trace corresponding curves, or roulettes, on the glass overlay.

- The blue point on the circumference of the disc traces a blue five-pointed star shape referred to as a hypocycloid. The green point on the radius of the disc traces a green curve inside the ring, and the red point on the extension of the radius of the disc traces a curve that extends past the radius of the ring. The German title of this model is: Erzeugung der Hypotrochoiden als soche mit freiem Centrum.

- References:

- Schilling, Martin,
*Catalog Mathematischer Modelle für den höheren mathatischen Unterricht*, Halle a.s., Germany, 1911, pp 56-57. Series 24, group 1, model 3.

- An online demonstration can be found at http://mathworld.wolfram.com/Hypotrochoid.html

- Location
- Currently not on view

- date made
- ca 1900

- maker
- Schilling, Martin

- ID Number
- 1982.0795.02

- catalog number
- 1982.0795.02

- accession number
- 1982.0795

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

## Hypotrochoid with overlay, Kinematic Model by Martin Schilling, model 4, number 332

- Description
- Around 1900, American mathematicians introduced ideas to their students using physical models like this one. This model is the fourth in a series of kinematic models sold by the German firm of Schilling to show a mechanical method for generating mathematical curves.

- The name hypotrochoid comes from the Greek word hypo, which means under, and the Latin word trochus, which means hoop. Thus hypotrochoids are curves formed by tracing a point on the radius or extension of the radius of a circle rolling around the inside of another stationary circle.

- Hypotochoids are members of the family of curves called trochoids; curves that are generated by tracing the motion of a point on the radius of a circle as it rolls along another curve, and include the cycloids (see item 1982.0795.05) and epitrochoids (see item 1982.0795.01). An infinite number of hypotrochoids can be formed, depending on the distance of the tracing point from the center of the rolling circle. The ratio of the radius of the rolling disc to the radius of the outer ring will determine the number of nodes the hypotochoid will have.

- In this model, the curves each have five nodes. Hypotochoids, for which the tracing point is on the extension of the radius, form curves that resemble petalled flowers and are called roses. The Spirograph toy produces various types of hypotrochoids. (See item 2005.0055.2) In the 18th century, it was found that shaping the sides of gear teeth, and the valley between teeth, using trochoidal curves reduced the torque of the rotating gears and allowed them to rotate more efficiently.

- As with Schilling’s model number 3 of a hypotrochoid, this model has a stationary toothed metal ring of radius 60 mm. A toothed disc of radius 36 mm rolls around the inside of the ring by the use of a crank below the baseplate. However, this model has a semitransparent glass disc of the same radius as the ring attached to the rotating disc.

- Traced on this glass disc is a red epitrochoid that would be formed by an imaginary point on the extension of the radius of a circle rotating on the outside of the disc in the model. A green point on this curve traces a green star-shaped hypotrochoid on the stationary glass overlay of the model as the disc is rotated.

- The hypotrochoid can also be generated by imagining a point on the extension of the radius of the rotating disc. An orange point on the green hypotrochoid aligns with the epitrochoid and shows how the epitrochoid can be generated from a hypotrocoid and vice-versa. The German title of this model is: Erzeugung der Hypotrochoiden als soche mit bedecktem Centrum.

- References:

- Schilling, Martin,
*Catalog Mathematischer Modelle für den höheren mathatischen Unterricht*, Halle a.s., Germany, 1911, pp 56-57. Series 24, group 1, model 4.

- Location
- Currently not on view

- date made
- ca 1900

- maker
- Schilling, Martin

- ID Number
- 1982.0795.03

- catalog number
- 1982.0795.03

- accession number
- 1982.0795

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

## Involutes of Circles, Kinematic Model by Martin Schilling, series 24, model 6, number 334

- Description
- Around 1900, American mathematicians introduced ideas to their students using physical models like this one. This model is the sixth in a series of kinematic models sold by the German firm of Schilling to show a mechanical method for generating mathematical curves.

- An involute of a circle is a curve that is produced by tracing the end of a string that is wrapped around a circle as it is unwound while being kept taut. It is the envelope of all points that are perpendicular to the tangents of a circle.

- As with the three trochoidal models, these curves were used in the shaping of gear teeth in the 18th century. Following that, it was discovered that shaping the teeth of gears using the curve formed by the involute of a circle also increases the efficiency of gearage. Surprisingly, there are many applications of noncircular gears, such as elliptical, triangular, and quadrilateral gears. (See model 1982.0795.06.)

- In this model a toothed circular gear of radius 13 mm is mounted on the baseplate and can be turned via a crank on the underside of the baseplate. A thick piece of beveled glass is mounted above the apparatus. A dark metal toothed bar 45 mm long is attached to the circular gear so that as the crank turns the circular gear, the toothed bar is forced past the circular gear and rotates round it.

- Perpendicular to the bar is a thin clip with three small colored balls. A blue ball is attached at the edge of the bar where the bar will touch the circle and traces the involute of the circle in blue on the glass. A red ball is placed 33mm in front of the toothed side of the bar and produces a “stretched” involute in red. A green ball is 45mm behind the toothed side of the bar traces another “stretched” involute in green. German title is: Erzeugung von Kreisevolventen.

- References:

- Schilling, Martin,
*Catalog Mathematischer Modelle für den höheren mathatischen Unterricht*, Halle a.s., Germany, 1911, pp 56-57. Series 24, group II, model 6.

- Online demo at Mathworld by Wolfram: http://mathworld.wolfram.com/Involute.html

- Location
- Currently not on view

- date made
- ca 1900

- maker
- Schilling, Martin

- ID Number
- 1982.0795.04

- catalog number
- 1982.0795.04

- accession number
- 1982.0795

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

## Cycloids, Kinematic Model by Martin Schilling, series 24, model 7, number 335

- Description
- Around 1900, American mathematicians introduced ideas to their students using physical models like this one. This model is the seventh in a series of kinematic models sold by the German firm of Schilling to show a mechanical method for generating mathematical curves.

- The cycloid solves the 17th-century problem posed by Swiss mathematician Johann Bernoulli known as the brachistochrone problem. This problem asks for the shape of the curve of fastest decent: the path that a ball would travel the fastest along under the influence of gravity.

- The cycloids are drawn by tracing the location of a point on the radius of a circle or its extension as the circle rolls along a straight line. Cycloids are members of the family of curves known as trochoids, curves that are generated by tracing the motion of a point on the radius of a circle as it rolls along another curve. The curve generated by a point on the circumference of the rolling circle is called an epicycloid, and a ball rolling on this curve (inverted) would travel faster than on any other path (the brachistochrone problem). Points either inside or outside the rolling circle generate curves called epitrochoids. The cycloid also solves the tautochrone problem, a curve for which a ball placed anywhere on the curve will reach the bottom under gravity in the same amount of time.

- An example of the application of the cycloid as a solution of the tautochrone problem is the pendulum clock designed by Dutch physicist Christopher Huygens. As the width of the swing of the pendulum decreases over time due to friction and air resistance, the time of the swing remains constant. Also, cycloidal curves are used in the shaping of gear teeth to reduce torque and improve efficiency.

- This model consists of a toothed metal disc linked to a bar that is toothed along one edge. A radius of the circle extending away from the bar has a place for a pin inside the circumference, a pin on the circumference, and a pin outside the circle. Rotating a crank below the baseplate of the model moves the circle along the edge of the bar, generating a curve above each point. The curves are indicated on the glass overlay of the mechanism. The curve generated by the point on the circumference of the circle is an epicycloid, depicted in blue on the glass; that generated by the point outside the circle is a prolate (from the Latin to elongate) cycloid, depicted in orange; and that generated by the point inside the circle is a curtate (from the Latin to shorten) cycloid, depicted in green. The German title of this model it: Erzeugung von Cycloiden (to produce cycloids).

- References:

- Schilling, Martin,
*Catalog Mathematischer Modelle für den höheren mathatischen Unterricht*, Halle a.s., Germany, 1911, pp 56-57. Series 24, group II, model 7.

- Online demo at Wofram Mathworld: http://mathworld.wolfram.com/Cycloid.html

- Location
- Currently not on view

- date made
- ca 1900

- maker
- Schilling, Martin

- ID Number
- 1982.0795.05

- catalog number
- 1982.0795.05

- accession number
- 1982.0795

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

## Twin Elliptical Gears, Kinematic Model by Martin Schilling, series 24, model 8, number 347

- Description
- Around 1900, American mathematicians introduced ideas to their students using physical models like this one. This model is the eighth in a series of kinematic models sold by the German firm of Schilling to show a mechanical method for generating mathematical curves.

- Many machines need to produce a back and forth motion, such as the back and forth motion of the rods of a locomotive that drives the wheels. This back and forth motion is achieved by converting circular motion (produced by the pistons of the steam engine) to linear motion (of the rods). One way of achieving this in a smooth way is through a
*quick return*mechanism. This model uses two ellipses that are held in constant contact, producing an “elliptical gear.”

- As one ellipse rotates around the other, the distance between the fixed focus of one ellipse and the free focus of the other remains constant. This can be seen in the model by the placement of the arm. As the ellipses rotate about each other, the speed of rotation increase as the ellipses move towards a side-by-side orientation, and slows as the ellipses move towards an end-to-end alignment. Thus the velocity increases and decreases periodically as the ellipses rotate. The velocity ratio of the rotating gear is the portion of the length of the top arm over one ellipse divided by the remaining length (over the other ellipse.) Mathematically this velocity ratio varies from
*e/(1-e)*to*(1-e)/e*where*e*is the eccentricity of the (congruent) ellipses. The cyclic nature of the velocity of this motion is known as a “quick-return” mechanism, which converts rotational motion into reciprocating or oscillating motion.

- This model employs two identical elliptical metal plates (major axis 8 cm, minor axis 5 cm). Both ellipses were fixed to the baseplate at their right foci (though one ellipse is now detached) while the other foci are free. This allows the two ellipses to rotate around each other while remaining in contact. An 8 cm rigid arm connects the fixed foci of one ellipse to the free foci of the other.

- Beneath the free foci of the left ellipse is a metal point. As the (now missing) crank below the baseplate is rotated, the point traces out a circle on the paper covering of the baseplate. Using the thumb hold at the midpoint of the arm, the two ellipses can be made to rotate around each other. A small ball-type joint at the ends of the major axis of each ellipse allows the two ellipses to join together when they are aligned end-to-end. The German title of the model is: Gleichläufiges Zwillingskubelgetriebe mit seinen Polbahnen (same shape transmitted by twin cranks with their poles).

- References:

- Cundy, H. M., Rollett, A. P.,
*Mathematical Models*, Oxford University Press, 1961, pp. 230-233.

- Schilling, Martin,
*Catalog Mathematischer Modelle für den höheren mathatischen Unterricht*, Halle a.s., Germany, 1911, pp. 56-57. Series 24, group III, model 8.

- Location
- Currently not on view

- date made
- ca 1900

- maker
- Schilling, Martin

- ID Number
- 1982.0795.06

- catalog number
- 1982.0795.06

- accession number
- 1982.0795

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