Howard_astronomical_regulator_clock.png
Size of this preview:
245 × 598 pixels
.
Other resolutions:
98 × 240 pixels
|
327 × 798 pixels
.
Summary
Description Howard astronomical regulator clock.png |
English:
Drawing of a precision astronomical regulator
clock
made by the E. Howard Clock Co., from a publication by Lick Observatory, CA, USA, 1887. The clock had a pendulum consisting of 4 containers of mercury that compensated for thermal expansion of the pendulum rod with temperature changes. It had a
deadbeat escapement
. It was installed at Lick Observatory and served to generate electric time signals that were distributed by telegraph wire to railroads and factories in the city of San Jose. For this it had internal switch contacts that generated signal every 2 seconds, connected to the 4 electrical terminal posts seen at the top of the clock. Alterations to image: cropped out second drawing showing clock with case open, and caption, which read: "The Howard mean-time clock".
|
Date | |
Source | Downloaded 2008-11-26 from Edward S Holden (1887) Publications of the Lick Observatory of the University of California, Vol.1 , Lick Observatory Trustees, p.72 on Google Books. |
Author | Edward S. Holden |
Permission
( Reusing this file ) |
Public domain in US - published prior to 1923 in US |
Licensing
Public domain Public domain false false |
This media file is in the
public domain
in the
United States
. This applies to U.S. works where the copyright has expired, often because its first
publication
occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See
this page
for further explanation.
|
||
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the
rule of the shorter term
for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See
Wikipedia:Public domain
and
Wikipedia:Copyrights
for more details.
|