Archives Center, National Museum of American History

Guide to the Greenleaf Pickard Notebooks and Nikola Tesla Patents

Collection ID:
Pickard, Greenleaf Whittier, 1877-1956
Physical Description:
1 Cubic foot
5 boxes
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.

  • Series 1: Greenleaf Pickard Notebooks, 1898-1941
  • Series 2: Nikola Tesla Patents, 1890, 1896 (bulk 1901-1918)

Biographical / Historical
Biographical / Historical
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.

Robert Ageton
Immediate Source of Acquisition
The collection was donated by the Cardwell Condenser Corporation, through Paul Meyer and David C. Kjeldsen in November 2004.
Custodial History
The collection was transferred from the Museum's Division of Information, Technology and Communication (now the Division of Medicine and Science) in 2006.
Processing Information
Processed by Robert Ageton, volunteer; supervised by Alison Oswald, archivist, 2009.

Using the Collection
Conditions Governing Use
Collection items available for reproduction, but the Archives Center makes no guarantees concerning copyright restrictions. Other intellectual property rights may apply. No copyright, patent, trademark or related interests were conveyed in the deed of gift. Archives Center cost-recovery and use fees may apply when requesting reproductions.
Conditions Governing Access
The collection is open for research use.
Preferred Citation
Greenleaf Pickard Notebooks, Archives Center, National Museum of American History.

Keywords table of terms and types.
Keyword Terms Keyword Types
Radio Topical Search Smithsonian Collections Search ArchiveGrid
Notebooks Genre Form Search Smithsonian Collections Search ArchiveGrid
Inventors Topical Search Smithsonian Collections Search ArchiveGrid
Radio -- History Topical Search Smithsonian Collections Search ArchiveGrid
Radio -- Receivers and reception Topical Search Smithsonian Collections Search ArchiveGrid
Cardwell Condenser Corporation (Lindenhurst, New York) Corporate Name Search Smithsonian Collections Search ArchiveGrid
Tesla, Nikola, 1856-1943 Personal Name Search Smithsonian Collections Search ArchiveGrid

Repository Contact
Archives Center, National Museum of American History
P.O. Box 37012
Suite 1100, MRC 601
Washington, D.C. 20013-7012