People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
For many years electrostatic machines like this one from Case Institute of Technology were considered essential tools for teaching the basic concepts of electrical science and saw significant use. Though in poor condition, this machine shows the basic components of a typical 19th century cylinder generator. The cylinder is set in wooden hubs and was turned by a direct-drive crank. Shards of material loose inside the cylinder may be remnants of the shellac used to hold the cylinder to the hubs. The leather rubbing pad with cloth flap provided the friction that generated the static charge. A mount post set opposite the rubbing pad held the missing metal collector that gathered the charge for experimental use.
During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. There are no extant makers marks so we are unable to determine the exact age or origin of this machine.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This incomplete unit shows the basic design of a typical 19th century cylinder machine, although the rubbing pad and collector are missing. Little is known of this machine’s background but it does demonstrate the international nature of scientific research. A label on the unit reads: “Swiss Section / Department III / Classe 300 / No. [104?] / Erziehungsdirection des Cantons / Bern.” A second label reads: “Exhibitor: The Board of Education of the Canton / of Bern” and the equivalent text in German and French. Stamped on the end of the base may be a reference to a maker: "G. Kupfer".
During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This machine was made in London by Edward Palmer (1803–1872) about 1840. The leather rubbing pad with a silk flap rides against one side of the cylinder and a brass prime conductor on the other side collects the charge with a brass comb. Both are mounted on insulating glass rods. A screw mechanism at the bottom adjusts the tension of the rubbing pad more precisely. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. Palmer sold microscopes and other scientific supplies from his shop on Newgate Street from about 1837 to about 1845 when he sold his business.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This machine, made around 1785, has a hand-cranked cylinder and a leather pad with silk cloth to mounted on one side. The mount is adjustable by means of the wooden screw set in the base. A prime conductor would be mounted opposite the rubbing pad but is missing from this unit. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. There is no extant maker's mark on the machine although it is of the type designed by Edward Nairne in the 1780s. Nairne (1726-1806) of England made electrical and other scientific devices.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This large electrostatic cylinder machine from the estate of Joseph Priestley was made around 1800 by Edward Nairne of Britain. Restored for exhibition in 1959, the machine and collector stand comprise most of the parts identified as belonging to the machine. Four additional collectors and parts of another stand are also associated with this object. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator.
Natural philosopher and free-thinker Joseph Priestley (1733-1804), emigrated from Britain to the United States in 1794. Among other accomplishments, Priestley is remembered for chemical and electrical research. Years after his death, his daughter sent an assortment of material to the Smithsonian, most of which was in poor condition. Curators at the time were uncertain how important the equipment may have been to Priestley’s research but preserved many of the items as examples of the type of equipment available in that era.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This ½ scale-model of Benjamin Franklin’s electrostatic generator was made in 1897 in the Smithsonian’s model shop based on drawings of a machine at the Franklin Institute in Philadelphia. Their machine “was received by the Franklin Institute from Dr. J. Redmond Coxe in 1826 who said that the machine had belonged to Franklin himself.” Smithsonian curator George C. Maynard paid $25 for drawings of the Franklin Institute’s machine and then displayed this model at the 1897 Nashville Exposition.
Early electrostatic machines generated a charge by spinning a globe against a pad. The charge could then be used directly in experiments or transferred from the globe to a Leyden jar. This model differs somewhat from the Franklin-style machine collected over a half century later (catalog # EM.325513) but shows the basic design of a rotating glass globe, leather rubbing pad and brass charge collector. The Smithsonian preserves many authentic pieces of the past but occasionally uses reproductions and models when original objects no longer exist or would be impossible to display.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This rudimentary cylinder machine is incomplete, missing the rubbing pad and charge collector. The construction appears very crude without the detailing or polish seen on a commercially-made device. Two U.S. coins were used as retaining washers on the crank axle. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. There is almost no background information about this object that came into the collections from the Merrimac Valley Textile Museum in 1975.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This machine, made around 1780, includes a steel T-shaped charge collector or prime conductor mounted to one side of the cylinder and a leather pad with silk cloth to mounted on the other side. Both mounts are adjustable by means of wooden screws set in the base. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. There is no extant maker's mark on the machine although it is of the type designed by Edward Nairne in the 1780s. Nairne (1726-1806) of England made electrical and other scientific devices.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This incomplete machine dates from about 1750 and appears to be Benjamin Franklin’s design. In the late 1740s, Franklin began investigating electricity with instruments supplied by friends in Britain. Scientific instruments of all types were in short supply in colonial America so Franklin supplemented his imported equipment with items of his own design. Early electrostatic machines generated a charge by spinning a globe against a pad. The charge could then be used directly in experiments or transferred from the globe to a Leyden jar. The hollow glass globe on this machine rubs against a leather pad seasoned with a specially formulated grease. The charge collector assembly, missing from this machine, consisted of brass pins that rode against the glass and carried the charge to a brass ball set on an insulating glass rod. Princeton University donated this machine in the 1960s and kept a second machine for display there. The exact origin of the two generators is uncertain but an oral tradition at Princeton associates both machines with Franklin.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This machine was made by the "Chambers’ National Lightning Protection Company," established around 1880 by Josephus C. Chambers, Cincinnati to market his lightning protection system. Apparently Chambers branched out into more general electrical devices after negative reviews of his lightning system were published.
During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. The Chambers machine shows a cruciform design with centrally-mounted cylinder that rubbed against a leather pad. A steel prime conductor with a comb on one end collected the charge. The glass rod serves as an insulator.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
For many years electrostatic machines like this one from Princeton were considered essential tools for teaching the basic concepts of electrical science and saw significant use. This table model is unmarked and of fairly crude workmanship. The wood frame holds a glass cylinder turned by a direct-drive crank although the handle is missing. Wooden hubs hold the cylinder in the frame. No rubbing pad or charge collector remain on this unit. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This original ink drawing of an electrostatic machine and components dates from about 1750. Signed "H: Carrington Fecit", the caption reads as follows: "A the Body of the Machine B the Globe C the Cufhion D the Spring E the Handle / F the Screw that fastens the whole Machine to the Table G the Slider and Screws that moves the Gun Barrell Nearer or Further / from the Globe HH the Supporters of the Gun Barrell II Crooked pieces that Sufpends Gun Barrell KK Silk Srings upon which / the Gun Barrell is Sufpended L Gun Barrell or Conductor M the Bells N Supporter & Ball to Equilibrition that moves by the Actract- / -tion of the finger or other Object O Bottle & Chain by w:ch the Shock is Given P the Ring Q the Plate R the Small Globe S Wire fixd to the / Ring & Conductor or Gun Barrells T the Hanging Plate V the Stand U the Small Images of thin paper Cut out at pleafure / WWW the feather & Wire".
Early electrostatic machines generated a charge by spinning a globe against a pad. The charge could then be used directly in experiments or transferred from the globe to a Leyden jar. The machine depicted in the drawing is the same type as a machine in the collection--catalog #1983.0190.01.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
For many years electrostatic machines like this one from Wesleyan University were considered essential tools for teaching the basic concepts of electrical science and saw significant use. Though in poor condition, this machine shows the basic components of a typical 19th century cylinder generator. The cylinder is set in brass hubs and was turned by a direct-drive crank. The leather rubbing pad with silk cloth provided the friction that generated the static charge. A collector set opposite the rubbing pad gathered the charge for experimental use. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. There are no extant maker’s marks so the exact age or origin of this machine is unknown at this time.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This portable generating machine from around 1760 comes with an experimental kit of accessories. Early electrostatic machines generated a charge by spinning a globe against a pad. The charge could then be used directly in experiments or transferred from the globe to a Leyden jar. The hand-cranked ball of sulfur on this machine rubbed against a leather pad. The pins on the brass rod set close to the ball transferred the charge from the ball to the rod, called a prime conductor. Suspended from a frame by insulating silk threads, the charged prime conductor allowed a researcher to show electrical properties like attraction, repulsion, and strength of charge. Accessories include pith balls, a chime of bells, a Leyden jar, and assorted plates, hooks and dischargers.
This machine is especially interesting as we have an original design drawing in the collection showing this type of machine--catalog #1988.0621.01.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This electrostatic machine was made by George Adams, Jr., of London and is set on a base that includes a drawer containing various experimental accessories. During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. The accessories include dischargers, along with a variety of hanging balls and rods that show electrical properties like attraction, repulsion, and strength of charge. Adams took over his father’s business after George Adams, Sr. died in 1772 and in 1784 published an Essay on Electricity with an Essay on Magnetism.
People from ancient times knew that rubbing certain materials and then touching something caused a spark. Studying what is called electrostatics laid the groundwork for understanding electricity and magnetism. Natural philosophers, scientists, and instrument makers created many ingenious devices to generate electrostatic charges starting in the 1600s. These machines varied in size and technique but all involved rotary motion to generate a charge, and a means of transferring the charge to a storage device for use.
This table-top electrostatic cylinder machine came to the Smithsonian along with a large assortment of equipment used by traveling lecturer and scientific showman Charles Came (1806-1881) and his successors. From the 1840s through the 1870s, Came traveled around New York State entertaining audiences with magic lantern shows and demonstrations of electrical phenomenon. His son-in-law Samuel Corby (1839-1913) continued the traveling shows for about 30 years after Came’s death, and John S. Fisher (1907-2002) revived the shows in the 1950s. Some of Came’s equipment was homemade and other pieces were purchased from commercial suppliers.
During the 1750s electrical researchers refined the design of electrostatic machines by replacing earlier spherical globes with a glass cylinder, a design used for many years. This change increased the surface area of the glass in contact with the rubbing pad and improved the efficiency of the generator. No maker’s markings appear on this machine so we do not know its origin.