Prototype_synthetic_quartz_autoclave_1959.jpg
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Summary
| Description |
English:
R. A. Sullivan and R. A. Ladice examining synthetic
quartz crystals
grown in the
autoclave
shown in
Western Electric
's pilot hydrothermal quartz plant in North Andover, Massachusetts in 1959. Until WW2, quartz crystals used in electronic equipment were natural crystals, mined in Brazil. Shortages due to military demand for quartz led to postwar efforts to culture synthetic quartz crystals. AT&T's Bell Labs first developed a process that was capable of industrial production, growing quartz crystals at high pressure and temperature in the autoclave shown. By the 1970s virtually all quartz used in the electronics industry was synthetic.
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| Date | |
| Source | Retrieved August 3, 2014 from Radio and Television News magazine, Ziff-Davis Publishing Co., Chicago, Vol. 61, No. 3, March 1959, p. 120 on American Radio History site |
| Author | Unknown author |
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Permission
( Reusing this file ) |
This 1959 issue of Radio and Television News magazine would have the copyright renewed in 1987. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. [1] Search of the Renewals for Periodicals for 1978 to present show no renewal entries for Radio and Television News . Therefore the magazine's copyright was not renewed and it is in the public domain. |
Licensing
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This work is in the
public domain
because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the
copyright was not renewed
. For further explanation, see
Commons:Hirtle chart
and
the copyright renewal logs
. Note that it may still be copyrighted in jurisdictions that do not apply the
rule of the shorter term
for US works (depending on the date of the author's death), such as Canada (70 years
p.m.a.
), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
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