Engineering, Building, and Architecture

• 

  Baldwin's Patent Model of a Flexible Beam Locomotive - ca 1842

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 2,759 issued to Matthias W. Baldwin on August 25, 1842. Baldwin’s invention was a design for a flexible beam truck for the driving wheels of a locomotive. The goal of the design was to increase the proportion of the engine’s total weight resting on driven wheels thus improving traction and thereby the ability of the engine to pull heavier loads. While then existing locomotives had multiple driven axles, their designs made them unsuitable for use on the tight curves that were common on American railroads at the time. Baldwin’s design allowed for multiple driving wheel axles to be coupled together in a manner that would allow each axle to move independently so as to conform to both to sharp curves and to vertical irregularities in the tracks. The “flexible beam” referred to heavy iron beams that were connected to each side of the engine’s frame with a vertical, spherical pin so that they could pivot horizontally and vertically in relation to the frame. The beams on each side of the frame moved independently of each other. At each end of the beams were journal boxes for the axles, and these boxes were constructed to an earlier Baldwin patent with cylindrical pedestals that allowed them to rotate vertically inside the beam. The result was that when rounding a curve one driving axle could move laterally in one direction while the other axle could move independently in the other direction thus adapting the wheels to the curve while at the same time keeping the axles parallel to each other. The coupling rods were made with ball-and-socket joints to allow them to adapt to the varying geometry due to lateral axle motion. While this geometry would also result in the coupling rod lengths varying as the axles moved laterally, in actual use the variation was very small – on the order of 1/32 of an inch – and was allowed for via a designed-in slackness in the bearings. The patent was applied by Baldwin to a large number of engines manufactured up until 1859 when the design was superseded by heavier and more advanced engines.

  The patent model is constructed of wood and metal and is mounted on rails attached to a wooden base. A brass plate attached to the boiler is inscribed with “M.W. Baldwin Philadelphia.” The boiler is painted wood as are the cylinders and coupling rods. The engine frame is steel, and the wheel rims are made of brass. The key element of the patent, the flexible beams are present on the front two axles. The beams and leaf springs are made of wood. The vertical pins appear to be made of steel. While the axle journal boxes are shown it appears the details of the cylindrical pedestals and other moving parts are not modelled.

  date made

  ca 1842

  ca. 1842

  patent date

  1842-08-25

  inventor

  Baldwin, Matthias W.

  ID Number

  TR.251274

  catalog number

  251274

  patent number

  2,759

  accession number

  48865

  Data Source

  National Museum of American History

• 

  Stevens Rocking Grate Bar, Patent Model

  Description

  This model was submitted to the U.S. Patent Office with the application for the patent issued to Francis B. Stevens, November 11, 1879, no. 221430.

  The model represents a grate surface formed of ordinary fish-bellied grate bars on each of the lower ends of which two journal bearings are formed to fit into and rest in two corresponding rounded socket bearings. The bar is made to rock in each of these bearings alternately to the right and left, so that the upper part of the grate overhangs the right-hand socket when rocked to the right, and the left-hand socket when rocked to the left. That the upper part of the grate bar will overhang the center on which it turns is the improvement claimed by the inventor.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1879

  patent date

  1879-11-11

  inventor

  Stevens, Francis B.

  ID Number

  MC.309217

  catalog number

  309217

  accession number

  89797

  patent number

  221,430

  Data Source

  National Museum of American History

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  Model of a J.W. Thompson "Buckeye" Steam Engine – ca 1875

  Description

  This is a model of the widely used and very successful "Buckeye" engine developed by J. W. Thompson and Nathan Hunt about 1875. It was one of the first of the high-speed, variable cut-off ("auto-matic") engines. The model has cut away sections to show the inner details of the steam cylinder and valve mechanism. The valve is a hollow-piston slide valve, taking steam at the center and passing it through the hollow center of the valve to ports through the walls of the valve. A sleeve like cut-off valve operates within the main valve to close the ports. The main valve is operated by a fixed eccentric on the crankshaft and the cut-off valve by a shifting eccentric, the position of which is varied by a centrifugal governor of the Thompson and Hunt type. In the image this governor is seen within the flywheel on the right. It is based on Thompson’s Patent Number 162,715 of April 27, 1875. The fixed eccentric drives the valve via the upper pushrod, and the variable, or shifting, eccentric operates the lower pushrod to control the cut off valve.

  date made

  ca 1875

  ID Number

  MC.309645

  catalog number

  309645

  accession number

  106,567

  Data Source

  National Museum of American History

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  Harrison Lubricator, Patent Model

  Description

  This model was submitted to the U.S. Patent Office with the application for the patent issued to A. L. Harrison, of Bristol, Connecticut, March 2, 1880, no. 225124.

  The model represents a steam-engine lubricator in which the oil is contained in a reservoir fitted with a balanced diaphragm upon both sides of which the steam pressure in the main acts. The unbalanced pressure required to force oil into the steam is atmospheric pressure obtained by the use of a vacuum chamber when the engine is operating condensing, or the hydrostatic pressure of a water column when the engine is operating noncondensing.

  The lubricator consists of an oval chamber divided by a flexible diaphragm. The space above the diaphragm contains the oil and is connected through a glycerine-filled sign glass to the steam chest or cylinder of the engine. The space below the diaphragm is connected to the steam pipe from the boiler, so that steam pressure acts on both sides of the diaphragm. A rod attached to the center of the diaphragm passes through suitable stuffing boxes to a piston in a cylinder below the diaphragm chamber. The space above the piston is connected to the condenser of the engine so that atmospheric pressure will exert an unbalanced force upon the under side of the piston, and through it upon the diaphragm, sufficient to force the oil out of the lubricator into the engine. When used with a noncondensing engine a water column in the steam pipe connecting to the under side of the diaphragm provides an unbalanced hydrostatic pressure on the diaphragm.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1880

  patent date

  1880-03-02

  inventor

  Harrison, Andrew L.

  ID Number

  MC.308704

  catalog number

  308704

  accession number

  89797

  patent number

  225,124

  Data Source

  National Museum of American History

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  Leuchsenring Rotary Water Engine, Patent Model

  Description

  This model was submitted to the U.S. Patent Office with the application for the patent issued to Robert Leuchsenring, of New Bedford, Massachusetts, March 9, 1880, no. 225226.

  This is a form of engine in which a drum-shaped rotor turns in a casing, which is eccentric to the center of the drum, so that the drum runs against one part of the casing and a crescent-shaped annular space is formed between the casing and the drum. Water is admitted tangentially to the drum to one side of and away from the point at which the drum and casing meet. The water impinges upon abutments on the drum, turns the drum, and discharges from the engine about two-thirds of the way around the casing. The abutments on the drum slide into the drum to pass the casing and are held against the casings by springs.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1880

  patent date

  1880-03-09

  inventor

  Leuchsenring, Robert

  ID Number

  MC.308709

  catalog number

  308709

  accession number

  89797

  patent number

  225,226

  Data Source

  National Museum of American History

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  Ericsson’s Patent Model of a Marine Steam Engine – ca 1858

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 20,782 issued to John Ericsson of New York, New York on July 6, 1858. The patent was for improvements in marine steam engines for powering a screw propeller. Mr. Ericsson’s goal was to maximize the power and compactness of the engine so that it could be located transversely and very low within a boat.

  His design consisted of two compact steam cylinders which were bolted together and mounted horizontally across the beam of the ship. They drove a single propeller shaft via a system of push rods and rocker arms. The design allowed for even application of power with reduced vibration and wear on engine parts and the frame of the ship.

  Mr. Ericsson was a prolific inventor; his inventions included many types of steam engines and associated apparatus as well as air engines. He was the designer of the USS Monitor for the North during the Civil War, and the engine for the Monitor was based on this patent.

  The patent model is made of brass and is mounted on a wood base representing a section of the hull of a ship. A brass plate on the base of the model is engraved “Screw Propeller Engine, J. Ericsson, Inventor.” All of the key elements of the patent are illustrated by the model which was provided with a crank on the propeller shaft to allow operation for demonstration. A full description of the operation of the engine along with complete diagrams can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

  date made

  1858

  patent date

  1858-07-06

  inventor

  Ericsson, John

  ID Number

  MC.251295

  catalog number

  251295

  patent number

  20,782

  accession number

  48865

  Data Source

  National Museum of American History

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  Worthington Direct-Acting Steam Pump, Patent Model

  Description

  This model was submitted to the U.S. Patent Office with the application for the patent issued to Henry R. Worthington, July 31, 1855, no. 13370.

  The model represents a double-acting water cylinder of a direct-connected steam pump so designed that toward the end of each stroke the pressure on each side of the water piston will be momentarily balanced to permit the expansion of steam already in the steam cylinder to quickly move the piston so that the steam valve operated by the piston will be quickly and positively opened for the return stroke.

  At the midpoint of the water cylinder is an opening connected to the force pipe through which the water is discharged. The piston is made of such length that this opening is uncovered to the suction side of the piston only near the end of the stroke. The effect of this is momentarily to subject both sides of the piston to the same water pressure and so relieve the steam piston of most of its resistance so that it can move rapidly and actuate the valve sharply and positively.

  The inventor refers to this as an improvement on the invention of “a new and improved method of insuring the action of steam valves in direct-acting pumping engines,” patented by himself and William H. Baker, April 3, 1849.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1855

  patent date

  1855-07-31

  inventor

  Worthington, Henry R.

  ID Number

  ER.309245

  accession number

  89797

  catalog number

  309245

  patent number

  13,370

  Data Source

  National Museum of American History

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  Wheelock Valve and Valve Seat Model

  Description

  This is a nicely made model of the valve and valve seat patented by Jerome Wheelock, of Worcester, Massachusetts, September 22, 1885, no. 326820.

  The model represents a wide gridiron slide valve assembled on a skeletonized taper plug, which serves as the valve seat and supports the rock shaft connected to the slide by links or “toggles.” The whole assembly is designed to fit into a taper hole bored into the cylinder block and connected by suitable ports to the cylinder. The advantage of this arrangement over ordinary plug valves is that it does not require that a valve seat be formed within the large cylinder casting, and it permits the delicate fitting of the valve to the valve seat to be performed at a work bench or upon a machine away from the engine.

  The complete Wheelock valve gear (U.S. patent number 326819) consists of one steam valve and one exhaust valve at each end of a cylinder with the rock arms of the exhaust valves permanently connected to the eccentric, so that the valve is at rest during part of the travel of the eccentric, while the steam valves are connected through a detachable latch so that they may be detached and closed quickly at any point during the stroke of the piston.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1885

  ID Number

  MC.310251

  catalog number

  310251

  accession number

  108073

  Data Source

  National Museum of American History

• 

  Ernst Plank Steam Engine Toy with Marx Lights

  Description (Brief)

  Ernst Plank produced this toy steam engine during the early 20th century. The toy has a tan fire box below a horizontal boiler with steam whistle, safety valve, and throttle. The steam line powers a small oscillating engine mounted on a two pole generator that provides electricity to twin Marx-manufactured lamps on metal scaffolding.

  Ernst Plank founded his company in Nuremburg, Germany in 1866. The company was well known for manufacturing a variety of metal toys like steam locomotives, stationary steam engines, early photography equipment, and magic lanterns until its dissolution in 1935.

  Location

  Currently not on view

  ID Number

  MC.329059

  catalog number

  329059

  accession number

  278175

  Data Source

  National Museum of American History

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  Higginson’s Patent Model of a Radial Steam Engine - 1877

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 196,451 issued to Andrew Higginson of Liverpool, England on October 23, 1877. The patent was for an improved design for reciprocating steam engines. His patent application described three designs. One was for a single rectangular piston, non-reversing engine. The second was for a three piston version that was non-reversing. The third design, and the one represented by this model, was for a three piston engine that could be reversed. The control lever seen at the right of the image of the model was for controlling the direction of rotation.

  Higginson provided two ports in the walls of each of the steam “cylinders.” As a piston oscillated up and down, a port in the skirt of the piston alternately exposed each of the ports in the wall. The control lever determined which port received steam and which acted as the exhaust and, thus, the direction of rotation. He claimed that the use of rectangular “cylinders” made the engine easier to construct and to obtain tight seals with the pistons.

  The patent model is constructed of brass and illustrates of the important elements of Higginson’s design. Although not visible in the image, the rear of the model has cut-away sections to reveal parts of the pistons and valve ports. A full description of the operation of the engine along with complete diagrams of the patent can be found in the patent document online at the United States Patent and Trademark Office website, www.uspto.gov.

  date made

  1877

  patent date

  1877-10-23

  inventor

  Higginson, Andrew

  ID Number

  MC.309194

  catalog number

  309194

  accession number

  89797

  patent number

  196,451

  Data Source

  National Museum of American History

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  Gilman’s Patent Model of a Valve for an Oscillating Steam Engine – ca 1851

  Description

  This model was filed with the application to the U.S. Patent Office for Patent Number 7,871 issued to Samuel H. Gilman of Cincinnati, Ohio on January 1, 1851. Mr. Gilman’s patent was for an improvement in the design of valve gear for an oscillating steam engine. An oscillating steam engine differs from a standard engine in that the steam cylinder is pivoted on the engine frame and oscillates up and down about the pivot as its connecting rod operates the crankshaft of the engine. In a standard engine, the cylinder is fixed in orientation, and the piston rod moves fore and aft within a crosshead which allows the connecting rod to pivot independently as the crankshaft revolves.

  Mr. Gilman did not claim as new an entire design of such an engine. He limited his claim to a modification of the tube that guides the pushrod which controls the steam valve. He included threads at the bottom of the rod and shaped that portion so that it could clamp and secure the ball at the end of the pushrod. When threaded into the collar on the valve housing it allowed the pushrod to move slightly to conform to the motion of the valve house. He referred to his improvement as a “tubular nut.” The patent did not elaborate on exactly what Mr. Gilman claimed for improved function.

  The model as shown in the image illustrates all of the key elements of the patent. It is constructed of metal and mounted on a wooden base. Diagrams showing the complete design can be found in the patent document online (www.USPTO.gov).

  Location

  Currently not on view

  date made

  1851

  patent date

  1851-01-01

  inventor

  Gilman, Samuel H.

  ID Number

  ER.325617

  accession number

  249602

  catalog number

  325617

  patent number

  7,871

  Data Source

  National Museum of American History

• 

  Carpenter Compound Hydraulic Engine, Patent Model

  Description

  The model was submitted to the U.S. Patent Office with the application for the patent issued to Oramill C. Carpenter, of Brooklyn, New York, December 17, 1878, no. 210915.

  The engine is essentially a hydraulic transmission, which takes motion from eccentric cams on a central shaft turned by a steam or other engine and transmits the motion to shafts on either side of and parallel to the central shaft. The inventor designed the engine to be applied to a streetcar, and the model is mounted in a miniature nickel-plated car truck.

  It is a 4-cylinder engine with opposed cylinders in groups of two. Single-acting plungers work in and out of the cylinders as the central shaft is turned. The head of each cylinder leads directly to another cylinder of reduced diameter in each of which a driven piston works through a longer stroke in time with the short stork of the driving piston. Valves for the relief of an excess pressure of liquid and spring-cushioned piston heads are described for smoother running.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1878

  patent date

  1878-12-17

  inventor

  Carpenter, Oramill C.

  ID Number

  MC.309252

  catalog number

  309252

  accession number

  89797

  patent number

  210,915

  Data Source

  National Museum of American History

• 

  Crosby Gas Engine Indicator

  Description

  Crosby Steam Gauge & Valve Co. of Boston, Massachusetts, manufactured this steam engine indicator, serial number 8619. It consists of a steel piston with four grooves, a vented brass cylinder, an internal spring (which is missing), a small drum with a spiral spring and a single record, and a brass stylus. Accompanying the indicator is a box with twelve springs, double wound, and some small tools.

  An engine indicator is an instrument for graphically recording the pressure versus piston displacement through an engine stroke cycle. Engineers use the resulting diagram to check the design and performance of the engine.

  A mechanical indicator consists of a piston, spring, stylus, and recording system. The gas pressure of the cylinder deflects the piston and pushes against the spring, creating a linear relationship between the gas pressure and the deflection of the piston against the spring. The deflection is recorded by the stylus on a rotating drum that is connected to the piston. Most indicators incorporate a mechanical linkage to amplify the movement of the piston to increase the scale of the record.

  When the ratio of the frequency of the pressure variation to the natural frequency of the system is small, then the dynamic deflection is equal to the static deflection. To design a system with a high natural frequency, the mass of the piston, spring, stylus, and mechanical linkage must be small, but the stiffness of the spring must be high. The indicator is subjected to high temperatures and pressures and rapid oscillations, imposing a limitation on the reduction in mass. Too stiff a spring will result in a small displacement of the indicator piston and a record too small to measure with accuracy. Multiplication of the displacement will introduce mechanical ad dynamic errors.

  The parameters of the problem for designing an accurate and trouble free recorder are such that there is no easy or simple solution. Studying the variety of indicators in the collection shows how different inventors made different compromises in their designs.

  Location

  Currently not on view

  maker

  Crosby Steam Gage & Valve Company

  ID Number

  MC.316798

  catalog number

  316798

  accession number

  228496

  patent number

  8619

  Data Source

  National Museum of American History

• 

  Carpenter's Pencil

  Description

  This pencil was grouped with a number of pencils found in the pocket of a tool belt used by Jillian Gross while working for Habitat for Humanity, a not-for-profit, non-government organization advocating affordable housing around the world. Carpenter pencils have an two wide flat sides to keep them from rolling. The graphite core is generally wide and flat, making it easy to mark course materials when using the flat side while using the thinner side for precision marks.

  When Hurricane Katrina struck the Gulf Coast in August 2005, Jillian Gross had worked with Habitat for Humanity for three years learning woodworking and house-building skills. Groups such as Habitat for Humanity marshaled volunteers, tools and lumber to step in when it became clear that normal avenues of housing assistance were overwhelmed.

  In November 2005, Habitat for Humanity launched “America Builds on the National Mall,” a demonstration house-building marathon in Washington, D.C. in which the basic components of 51 homes were assembled within a week and shipped to the Gulf Coast. Upon completion of the project Ms. Gross, one of the house building leaders during this event, donated her tool belt, tools and protective wear to the Smithsonian Institution.

  Location

  Currently not on view

  ID Number

  2005.0276.27

  catalog number

  2005.0276.27

  accession number

  2005.0276

  Data Source

  National Museum of American History

• 

  Desmond Injector, Patent Model

  Description

  This model was submitted to the U.S. Patent Office with the application for the patent issued to John Desmond, of Cincinnati, Ohio, October 8, 1901, no. 683914; assigned to the Lunkenheimer Co.

  Features of this injector are the construction of the starting lever, which with one motion operates both the steam and overflow valves and also permits the overflow valve to close independently of the lever; a removable ring of resistant metal inserted in the combining tube at its smallest diameter to receive the corroding action of the jet at that point; and an arrangement of steam and water passages designed to prevent the raising of the temperature of the feed water to such a temperature as to deposit scale within the tubes of the injector.

  Reference:

  This description comes from the 1939 Catalog of the Mechanical Collections of the Division of Engineering United States Museum Bulletin 173 by Frank A. Taylor.

  Location

  Currently not on view

  date made

  1901

  patent date

  1901-10-08

  inventor

  Desmond, John

  ID Number

  MC.309190

  catalog number

  309190

  accession number

  89797

  patent number

  683,914

  Data Source

  National Museum of American History

• 

  Stein Steam Engine Indicator

  Description

  This steam engine indicator, serial number 24296, was manufactured by Stein Sohn of Hamburg, Germany. It consists of a brass piston with two grooves; a vented brass cylinder; an internal, double wound spring, which can be changed; and a brass holder for a pencil. The large drum is damaged and cannot be taken apart for inspection, but it probably contains a spiral spring. Accompanying the indicator is a box with two springs, a scale reduction parallelogram, a tri-square pulley and bracket, and a knob to adjust the pencil pressure on the drum.

  An engine indicator is an instrument for graphically recording the pressure versus piston displacement through an engine stroke cycle. Engineers use the resulting diagram to check the design and performance of the engine.

  A mechanical indicator consists of a piston, spring, stylus, and recording system. The gas pressure of the cylinder deflects the piston and pushes against the spring, creating a linear relationship between the gas pressure and the deflection of the piston against the spring. The deflection is recorded by the stylus on a rotating drum that is connected to the piston. Most indicators incorporate a mechanical linkage to amplify the movement of the piston to increase the scale of the record.

  When the ratio of the frequency of the pressure variation to the natural frequency of the system is small, then the dynamic deflection is equal to the static deflection. To design a system with a high natural frequency, the mass of the piston, spring, stylus, and mechanical linkage must be small, but the stiffness of the spring must be high. The indicator is subjected to high temperatures and pressures and rapid oscillations, imposing a limitation on the reduction in mass. Too stiff a spring will result in a small displacement of the indicator piston and a record too small to measure with accuracy. Multiplication of the displacement will introduce mechanical ad dynamic errors.

  The parameters of the problem for designing an accurate and trouble free recorder are such that there is no easy or simple solution. Studying the variety of indicators in the collection shows how different inventors made different compromises in their designs.

  Location

  Currently not on view

  ID Number

  MC.325993

  catalog number

  325993

  accession number

  308486

  Data Source

  National Museum of American History

• 

  Star Steam Engine Indicator

  Description

  The Star Brass Mfg. Co. manufactured this steam engine indicator, serial number 760. It consists of a steel piston with one groove; a vented brass cylinder; an external, double wound spring, which can be changed; a small drum with a spiral spring and a single record. The stylus is missing.

  An engine indicator is an instrument for graphically recording the pressure versus piston displacement through an engine stroke cycle. Engineers use the resulting diagram to check the design and performance of the engine.

  A mechanical indicator consists of a piston, spring, stylus, and recording system. The gas pressure of the cylinder deflects the piston and pushes against the spring, creating a linear relationship between the gas pressure and the deflection of the piston against the spring. The deflection is recorded by the stylus on a rotating drum that is connected to the piston. Most indicators incorporate a mechanical linkage to amplify the movement of the piston to increase the scale of the record.

  When the ratio of the frequency of the pressure variation to the natural frequency of the system is small, then the dynamic deflection is equal to the static deflection. To design a system with a high natural frequency, the mass of the piston, spring, stylus, and mechanical linkage must be small, but the stiffness of the spring must be high. The indicator is subjected to high temperatures and pressures and rapid oscillations, imposing a limitation on the reduction in mass. Too stiff a spring will result in a small displacement of the indicator piston and a record too small to measure with accuracy. Multiplication of the displacement will introduce mechanical ad dynamic errors.

  The parameters of the problem for designing an accurate and trouble free recorder are such that there is no easy or simple solution. Studying the variety of indicators in the collection shows how different inventors made different compromises in their designs.

  Location

  Currently not on view

  date made

  ca 1907

  maker

  Star Brass Manufacturing Company

  ID Number

  MC.319483

  catalog number

  319483

  accession number

  237917

  Data Source

  National Museum of American History

• 

  Slave Dial to Tower Clock

  Description

  In places that required many clocks—factories, office and public buildings, or schools—time was often distributed by a system of "master" and "slave" clocks. In such a system, a central timekeeper, the master clock, sent periodic impulses, usually electric or pneumatic, to any number of secondary or slave clocks. These slave clocks could be located anywhere, without regard for convenience of winding, because they needed none. The master clock could also drive other time signals like classroom bells, factory whistles, or time stamps. More economical to install and more convenient to maintain than an equal number of independent clocks, the system also ensured that all dials within the system agreed.

  The museum collection contains such a timekeeping system. The system's master clock (Cat. 310,569), built by E. Howard and Company of Boston, is a mechanical tower clock movement equipped with electrical contacts. Once a minute the escapement, through a pair of rotary switches, closes an electrical circuit and sends an impulse to the slave dial (Cat. 310,570), where electromagnets advance the hands. Batteries at the base of the master clock supply current.

  This clock and dial were components of a system that served the Smithsonian between about 1881 and 1932. First housed in the north tower of the Arts and Industries Building, the clock movement distributed impulses to eighteen dials in that building and the Castle, the Smithsonian's earliest building. Tunnels under the floors carried the wiring. The clock room also housed a telephone switchboard, a watchman's clock, a central burglar alarm, and call bells—all of which, like the time distribution system, relied on the newly harnessed power of electricity. "Indeed," boasted the Smithsonian's annual report for 1881, "it is believed that in no building in the world, with the exception of the Grand Opera House in Paris, is there so perfect and complete an application of electricity to practical services."

  Date made

  1880

  ID Number

  ME.310570

  catalog number

  310570

  accession number

  123081

  Data Source

  National Museum of American History

• 

  Weeden No. 101 Electric Motor

  Description (Brief)

  The Weeden no. 101 electric generator was produced by the Weeden Manufacturing Company of New Bedford, Massachusetts from 1912 until 1918. The toy is an electromagnetic generator, producing a direct electric current through the rotation of a wire coil in a magnetic field. The center axel of the generator could be connected to the flywheel of a Weeden steam engine, rotating the center coil, turning mechanical power into electricity.

  The Weeden Manufacturing Company was founded in New Bedford, Massachusetts by William M. Weeden in the early 1880s, originally producing a variety of tinplate household items. In 1884 it introduced the Weeden No. 1 Steam engine as “a new and great premium for boys” who were subscribers to the Youth’s Companion magazine. Weeden made over a hundred different models of toy steam engines until the company ceased operations in 1952.

  Location

  Currently not on view

  date made

  ca 1900

  ID Number

  MC.329036

  catalog number

  329036

  accession number

  278175

  Data Source

  National Museum of American History

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  Plate 67. Quarles' Mills, on the North Anna

  Description

  Text and photograph from Gardner's Photographic Sketchbook of the War, Vol. II. Negative by Alexander Gardner, text and positive by Alexander Gardner.

  Another scene of picturesque beauty on this interesting stream. The building is a time-worn, weather-stained structure, not altogether free from the suspicion of harboring reptiles. In the river the negroes caught delicious terrapin, and the soldiers varied their rations with messes of catfish. A temporary bridge, constructed from the timber found at the mill, was thrown across, just below the dam, and many were the misgivings, when the rains caused a rise in the river, threatening to float away the frail structure, and sever communications with the opposite bank, a disaster which happily did not take place. In the grassy fields above the mill, the tents of Grant's and Meade's headquarters, seldom far apart, were pitched for a few days. Among the prisoners brought to this place was a woman, clad in rebel gray. She was taken, mounted astride a bony steed, apparently performing the duties of a scout, but claimed to belong to a battery of artillery. A degraded, wild specimen of humanity, of Irish extraction, with a shock of tangled black hair hanging in elf locks down to her shoulders, she proved the centre of interest to the idlers of the camp. At these she would occasionally hurl stones, being particularly hostile towards the negroes, who gave her a wide berth, to avoid the missiles, which she threw with considerable force and accuracy. The North Anna, meeting with its sister stream, the South Anna, a few miles lower down, forms the sluggish Pamunkey, which in its turn combines with the Mattapony, and becomes the York river, under which name the associated streams fall into the Chesapeake.

  Location

  Currently not on view

  date made

  1865-05

  maker

  Gardner, Alexander

  ID Number

  1986.0711.0283.17

  accession number

  1986.0711

  catalog number

  1986.0711.0283.17

  Data Source

  National Museum of American History

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