Exposed Intel DX4 processor. This is one of several versions of the DX4, “a write-through” type with a 100 MHz speed. Chip removed from an award plaque, one of twenty-two awards removed from the walls of the Hillsborro Fab in Oregon by Andy Grove for donation to the Smithsonian. Award nameplate: "Intel / Intel DX4 TM Processor / Albert Yu / World's Fastest 486 / One Million Shipped / September 1994." The circuitry includes inherent capacitance.
Brown fur pelt used in static electricity generation. Identified on box as mink but may be ferret fur thru conversations with outside restorationists in the field of electrostatics. Consultation took place in the mid 1980s while restoring the friction machine for educational demonstrations related to the "Static Hall" exhibition.
Glass rod for electrostatic experiments and demonstrations. A hollow glass tube, no extant markings. When rubbed with fur an electrostatic charge is generated.
Voltaic Pile, wooden base and cap with three glass uprights containing alternating discs of zinc and silver. Felt pads are interleaved between the discs.
Insulated wire reel for electrostatic experiments. The experimental purpose of this device is uncertain. It may be for conducting charge from a kite string, or possibly for testing strength of charge over distances.
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.
RCA / NBC "camera box" condenser microphone on stand with cord and plug. Condenser microphone with three stages of amplification made possible by development of vacuum tubes free of operation noises. Transmits all sound frequencies registered at the microphone diaphragm. High cost of maintenance of three stages of amplification in the case made other microphone types more desirable. Black metal cube on short stand and base. Nameplate: RCA model AA4088, serial no. 3106. Cord and plug attached.
Set of 4 Leyden Jars in a wooden box. Each has a wooden cap with a brass rod passing through the cap. A small chain runs from the rod to the bottom of each jar. A brass rod connects the four jars together. The jars sit on a common metal plate which is connected to a brass rod running through the side of the box. A brass tag on the side of the box is marked: "E. Leybold's Nachfolger Cologne, Germany." Princeton #H43.
Homemade glass plate condenser for amateur radio use. Later called a capacitor these devices store an electrical charge. Consists of three pieces of window glass (1 double-strength, 2 single-strength), with 2 metal inserts each connected to a contact. One insert is set between each glass pane, one insert is metal foil, the other is metal mesh. Two bands of tar tape holds panels together. Flat plate condensers were first invented by Benjamin Franklin around 1749 as a variation of the Leyden jar.
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.
Spiral Rotary Discharge Apparatus. Brass trileg ring with a center glass column and seven glass tubes around perimeter. Base ring with three turned legs and braces to center. Center column solid glass 7/8" diameter, brass ferrule each end, upper has 1" diameter. brass sphere and removable spike 3.75" long, overall 14.75" long, seven tubes, 11/16' outside diameter, spiral foil inside each, brass ferrules each end, upper has sphere 3/4" diameter, overall 15" long. One glass tube is broken off and missing (only the base cup with a glass shard remains), and a replacement has been made and set in place. One other tube is broken near the top although pieces do not seem to be missing. The original rotor is missing and a replacement has been installed.
The hook on the center column connects to an electrostatic machine. As the machine generates a charge, the user sets the top rotor spinning. As the rotor approaches each grounded outer column, it is attracted to the brass cap which has an opposite charge. When the rotor and the cap are in close proximity, a spark jumps from the rotor to the cap. Now charged alike, the cap repels the rotor, moving it toward the next column. The electrical charge runs through the foil tape in the outer column toward ground, creating flashes of light at each narrow point on the tape. The base ring conducts the electricity to ground, returning the outer columns to an opposite charge before the rotor approaches the next column to repeat the discharge process.
