An illustration of brine being raised from the bottom of a salt well, one of several illustrated drawings of the Chinese salt industry printed in the Tiangong Kaiwu encyclopedia of 1637, written by Song Yingxing (1587-1666). This illustration can be found on page 120 of E-tu Zen Sun and Shiou-Chuan Sun's English translation of the Tiangong Kaiwu (Pennsylvania State University Press).

This picture was taken from

http://sts.nthu.edu.tw/mengxi/story08.html

This image is in the public domain because under the Copyright law of the United States, originality of expression is necessary for copyright protection, and a mere photograph of an out-of-copyright two-dimensional work may not be protected under American copyright law. The official position of the Wikimedia Foundation is that all reproductions of public domain works should be considered to be in the public domain regardless of their country of origin (even in countries where mere labor is enough to make a reproduction eligible for protection). PD Public domain false false

This image is in the public domain in the United States. In most cases, this means that it was first published prior to January 1, 1929 (see the template documentation for more cases). Other jurisdictions may have other rules, and this image might not be in the public domain outside the United States. See Wikipedia:Public domain and Wikipedia:Copyrights for more details. PD-US Public domain in the United States //en.wikipedia.org/wiki/File:Tiangong_Kaiwu_Raising_Brine_Salt_Well.gif

This file is a candidate to be copied to Wikimedia Commons. Any user may perform this transfer; refer to Wikipedia:Moving files to Commons for details. If this file has problems with attribution, copyright, or is otherwise ineligible for Commons, then remove this tag and DO NOT transfer it; repeat violators may be blocked from editing. Other Instructions Endorse this file for transfer by adding |human=<your username> to this Template. If this file is freely licensed, but otherwise unsuitable for Commons (e.g. out of Commons' scope, still copyrighted in the US), then replace this Template with {{Do not move to Commons|reason=<Why it can't be moved>}} If you think that a local copy of this file should be retained, then replace this Template with {{Keep local|reason=<Why a local copy is needed>}} Please ensure that the file has a properly descriptive and unambiguous name before transferring; see Wikipedia:File mover#What files should be renamed? for details.

This file was suggested for transfer by a bot (User:Svenbot). Please verify that this file is suitable for Commons before transferring it.