One of two telephones used by Alexander Graham Bell in a demonstration that took place between Boston and Salem, Massachusetts on November 26, 1876. Critical features are the iron diaphragm (seen as a black circular disc mounted on the vertical wooden support), two electromagnets (seen in white, facing the diaphragm) and a horseshoe permanent magnet (lying horizontal, pressed against the electromagnets).
When used as a transmitter, sound waves at the mouthpiece cause the diaphragm to move, inducing a fluctuating current in the electromagnets. This current is conducted over wires to a similar instrument, acting as a receiver. There, the fluctuating current in the electromagnets causes the diaphragm to move, producing air vibrations that can be heard by the ear. This was a marginal arrangement, but it worked well enough to be employed in the first commercial services in 1877. The magneto receiver continued to be used, but the transmitters were soon replaced by a carbon variable-resistance device designed by Francis Blake and based on a principle patented by Thomas Edison.
This Sony "Walkman" portable tape player dates from the early 1980s. Originally introduced in 1979 as the “Soundabout,” two people could listen simultaneously while a small microphone permitted them to converse without removing their headsets. Powered by a 9-volt battery, the recorder sold well until the decline of the cassette format in the mid 2000s.
Until the middle of the twentieth century portable recording equipment could be quite heavy. The introduction of small transistor radios in 1954 marked a new era in portable entertainment. Philips’ invention of a compact recording cassette in 1962 provided a convenient medium for music distribution.
Integrated circuits consist of electric components such as transistors, resistors, capacitors, and metallic interconnects manufactured at a nanometer scale on a silicon chip. Chip designers are constantly seeking to pack more components into less space making the engineering requirements of chip design almost an art. In the 1970s and early 1980s design engineers began to personalize their chip designs by leaving microscopic images etched inside the chips’ functioning design. These images took a variety of forms; company logos, funny animals, comic characters, or inside jokes between the engineering team. This hidden art helped to show that chip layers were correctly aligned and could prove that a competitor had stolen a chip design. Once chip designs were covered by copyright in 1984, chip art became a way for engineers to assert their individuality into the mass production of chip manufacturing.
This 21msp50/55/56 digital signal processor chip was created by Analog Devices Incorporated around 1994. The chip contains an image of a fire-breathing Godzilla.
This is an Edison carbon lamp with Thomson-Houston base and asphalt-coated filament that was developed around 1891. The lamp's base differed depending on the manufacturer of the lamp. Edison, Westinghouse, Thomson-Houston and other makers devised differing ways to attach a lamp to a fixture. Companies quickly began making adapters or, as in this case, making their own lamps with competitors’ bases.
The completion of the first transatlantic telegraph cable in 1858 was a cause for much celebration on both sides of the Atlantic. Tiffany & Company of New York purchased the cable remaining on board the USS Niagara after the successful completion of the cable and sold 4-inch sections as souvenirs. Each section of cable was banded at the ends with brass ferrules and had a brass plaque that read “ATLANTIC TELEGRAPH CABLE/GUARANTEED BY/TIFFANY & CO./ BROADWAY • NEW YORK • 1858.” The cable souvenirs originally sold for 50 cents and came with a reproduced letter of authenticity from Cyrus W. Field, the pioneer of the transatlantic cable system. The jubilation turned to jeers when the cable failed a few weeks later, and Tiffany never sold its supply of cable. In 1974 Lanello Reserves began reselling the transatlantic cable, and donated this object to the Smithsonian.
Jack Kilby’s demonstration of the first working integrated circuit (IC) in 1958 revolutionized the field of microelectronics. Instead of using discrete transistors, resistors, and capacitors to form a circuit, Kilby’s IC design integrated a transistor, a capacitor, and the equivalent of three resistors all on the same chip. Kilby fabricated three types of circuits to test his idea: a flip flop, a multi vibrator and a phase shift oscillator. This chip is the phase-shift oscillator.
The first IC was made out of a thin slice of germanium (the light blue rectangle) as a bulk resistor and contained a single bipolar transistor (under the large aluminum bar in the center). It had four input/output terminals (the small vertical aluminum bars), a ground (the large bar on the far right), and wires of gold. The microchips of today have been improved by hundreds of innovations, but Kilby’s prototype was an important early step.
This model CP-5203 45 RPM turntable was manufactured by the RCA Victor Company around 1949. The black plastic motor-mount and turntable are housed in a wooden case with brass hinges and brass-plated corners. The turntable could be locked with the key; opening the case reveals a brass plate that reads “RCA Victor.” In 1947 RCA Victor introduced the “Berkshire” line of custom built combination radio-phonograph-television cabinets meant to serve as a home’s entertainment center. In 1949 RCA Victor introduced its 45 rpm format records and issued this 45 rpm turntable attachment to the Berkshire line to allow it to play the new format.
This Western Union Telegraph Company stock ticker was produced during the early 20th century. The ticker received stock information via a telegraph line and printed out a company’s abbreviated name and stock price on the spool of paper tape. After the Civil War, the volume of stocks traded rose sharply with American corporations’ need for investment capital. The 1867 invention of the stock ticker, transmitting up-to-the-minute share prices over telegraph lines, helped modernize the stock exchange.
This telegraph receiver is associated with United States patent 4,453 granted April 11th, 1846 to Samuel Morse. The patent covered the use of a magnet in the telegraph receiver to amplify current from the battery and magnet connected to the main telegraph line. This enabled the telegraph to receive messages over longer lines. The patent also specified a combination of apparatuses to move and mark a paper roll in order to record the incoming message.