Checked content

File:Clock Tower from Su Song's Book.JPG

Description

Chinese mechanical and horological engineering from the Song Dynasty; this diagram provides an overall general view of the inner workings and armillary sphere of Su Song's clocktower built in Kaifeng. The drawn illustration comes from Su Song's book Xin Yi Xiang Fa Yao published in the year 1092. On the right is the upper reservoir tank with the 'constant-level tank' beneath it. In the centre foreground is the 'earth horizon' box in which the celestial globe was mounted. Below that are the time keeping shaft and wheels supported by a mortar-shaped end-bearing. Behind this is the main driving wheel with its spokes and scoops. Above that are the left and right upper locks with an upper balancing lever and upper link.
Date 14 August 2007
Source Page 451 of Joseph Needham's book Science and Civilization in China: Volume 4, Part 2, Mechanical Engineering.
Author PericlesofAthens
This is a faithful photographic reproduction of an original two-dimensional work of art. The work of art itself is in the public domain for the following reason:
Public domain This image (or other media file) is in the public domain because its copyright has expired.

This applies to Australia, the European Union and those countries with a copyright term of life of the author plus 70 years.

Dialog-warning.svg You must also include a United States public domain tag to indicate why this work is in the public domain in the United States. Note that a few countries have copyright terms longer than 70 years: Mexico has 100 years, Colombia has 80 years, and Guatemala and Samoa have 75 years, Russia has 74 years for some authors. This image may not be in the public domain in these countries, which moreover do not implement the rule of the shorter term. Côte d'Ivoire has a general copyright term of 99 years and Honduras has 75 years, but they do implement the rule of the shorter term.
This file has been identified as being free of known restrictions under copyright law, including all related and neighboring rights.

The official position taken by the Wikimedia Foundation is that "faithful reproductions of two-dimensional public domain works of art are public domain, and that claims to the contrary represent an assault on the very concept of a public domain". For details, see Commons:When to use the PD-Art tag.
This photographic reproduction is therefore also considered to be in the public domain.

Please be aware that depending on local laws, re-use of this content may be prohibited or restricted in your jurisdiction. See Commons:Reuse of PD-Art photographs.
The following pages on Schools Wikipedia link to this image (list may be incomplete):

Metadata

This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified file.
Camera manufacturer SONY
Camera model DSC-T1
Exposure time 1/8 sec (0.125)
F-number f/3.5
ISO speed rating 100
Date and time of data generation 11:36, 15 August 2007
Lens focal length 6.7 mm
File change date and time 11:36, 15 August 2007
Y and C positioning Co-sited
Exposure Program Normal program
Exif version 2.2
Date and time of digitizing 11:36, 15 August 2007
Image compression mode 8
Exposure bias 0
Maximum land aperture 3.625 APEX (f/3.51)
Metering mode Pattern
Light source Unknown
Flash Flash fired, strobe return light detected, compulsory flash firing
Colour space sRGB
Custom image processing Normal process
Exposure mode Auto exposure
White balance Auto white balance
Scene capture type Standard
Contrast Normal
Saturation Normal
Sharpness Normal

Want to know more?

Wikipedia for Schools brings Wikipedia into the classroom. SOS Children's Villages believes that a decent childhood is essential to a happy, healthy. Our community work brings families new opportunities through education, healthcare and all manner of support. Go to http://www.soschildrensvillages.org.uk/sponsor-a-child to sponsor a child.