Greenleaf Pickard Notebooks and Nikola Tesla Patents
name: label: Creator
content: Pickard, Greenleaf Whittier, 1877-1956
label: Donor
content: Cardwell Condenser Corporation (Lindenhurst, New York)
label: Names
content: Tesla, Nikola, 1856-1943
topic: label: Topic
content: Radio
label: Topic
content: Inventors
label: Topic
content: Radio -- History
label: Topic
content: Radio -- Receivers and reception
acqinfo: label: Provenance
content: The collection was donated by the Cardwell Condenser Corporation, through Paul Meyer and David C. Kjeldsen in November 2004.
creator: label: Creator
content: Pickard, Greenleaf Whittier, 1877-1956
setName: label: See more items in
content: Greenleaf Pickard Notebooks and Nikola Tesla Patents
abstract: label: Summary
content: The collection documents Greenleaf Whittier Pickard, an engineer, and his experiments in wireless technology. Materials include Greenleaf Pickard notebooks and patents issued to Nikola Tesla.
bioghist: label: Biographical / Historical
content: Dr. Greenleaf Whittier Pickard was born February 14, 1877, in Portland, Maine and died on January 8, 1956 in Newton, Massachusetts.  Dr. Pickard was a grandnephew of the poet John Greenleaf Whittier, and was a graduate of Harvard University and the Massachusetts Institute of Technology. In 1899 he received a grant from the Smithsonian Institution to support his wireless research at Blue Hill Observatory in Milton, Massachusetts.  He was an engineer at the American Telephone and Telegraph Company (1902-1906); and after 1945 he was head of Pickard and Burnes, an electronics engineering firm.

Pickard discovered that a number of naturally occurring crystalline minerals could detect radio signals.  The contact between a fine metallic wire (cat's whisker) and the surface of certain crystalline materials rectifies and demodulates high frequency alternating currents, such as those produced in a receiving antenna by radio waves. Pickard patented a crystal detector in 1906.  The point-contact rectifier was the forerunner of the transistor invented in 1948.  Pickard conducted experiments to determine the effect of sun and sunspots, meteor showers, atmosphere pressure and temperature on reception. He contributed to the development of the direction finder, and noted in 1908 that errors in reading radio compasses might be caused by buildings, trees, and other objects.
physdesc: label: Extent
content: 1 Cubic foot (5 boxes)
unitdate: label: Date
content: 1898-1941
custodhist: label: Custodial History
content: The collection was transferred from the Museum's Division of Information, Technology and Communication (now the Division of Medicine and Science) in 2006.
dataSource: label: Archival Repository
content: Archives Center, National Museum of American History
identifier: label: Identifier
content: NMAH.AC.0915
objectType: label: Type
content: Collection descriptions
label: Type
content: Archival materials
label: Type
content: Notebooks
arrangement: label: Arrangement
content: Series 1: Greenleaf Pickard Notebooks, 1898-1941

Series 2: Nikola Tesla Patents, 1890, 1896 (bulk 1901-1918)
processinfo: label: Processing Information
content: Processed by Robert Ageton, volunteer; supervised by Alison Oswald, archivist, 2009.
genre_format: label: Genre/Form
content: Notebooks