Aobotu 熬波圖

Aobotu 熬波圖 "Illustrated boiling of sea water" is an illustrated book about salt production written during the Yuan period 元 (1279-1368) by Chen Chun 陳椿 (1293-1335).

He compiled the book on the base of older texts drafted when he was overseer of the salines at Xiasha 下砂場. It contains 47 illustrations with explanations to all steps of the production of salt from erecting furnaces, collecting firewood and boiling down the brine.

The Aobotu is included in the Ming-period 明 (1368-1644) encyclopaedia Yongle dadian 永樂大典. Five illustrations are missing. In this version it was reproduced in the series Siku quanshu 四庫全書. The text, without illustrations, is included in the series Xuetang congkan 雪堂叢刊, with the title of Aobotu yong 熬波圖咏.

Illustration No. 20 擔灰攤晒圖 "Transporting the grey (raw material) to expose it to the sun"

Illustration No. 27 打滷入船圖 "Filling the brine into boats"

Illustration No. 37 鑄造鐵柈圖 "Melting down iron to make shovels"

Illustration No. 42 上滷煎鹽圖 "Filling in the brine to boil it down to salt"

The Aobotu is also included in the series Jishi'an congshu 吉石盦叢書, Xuetang congke 雪堂叢刻 and Shanghai zhanggu congshu 上海掌故叢書.

Yoshida Tora's 吉田寅 study and translation of the Aobotu from 1983 (Gendai seien gijutsu shiryō "Gōhazu" no kenkyū: tsuketari "Gōhazu" yakuchū 現代製塩技術資料「熬波図」の研究: 附「熬波図」訳註) was translated into English by Hans Ulrich Vogel (1993), Salt Production Techniques in Ancient China: The "Aobo tu" (Leiden: Brill).