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"
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).
|1||各團竈座圖||The hearth places of each unit|
|2||築壘圍墻圖||Stamping and piling up an encircling wall|
|3||起盖竈舍圖||Setting up and roofing the hearth houses|
|4||團内便倉圖||The benefitting storehouse in the unit|
|5||褁築灰淋圖||Constructing the ash-leaching [basin]|
|6||築疊池井圖||The construction of ponds and wells|
|7||盖池井屋圖||Building shelters for the ponds and wells (illustration missing)|
|8||開河通海圖||Opening a channel with connection to the sea|
|9||埧堰蓄水圖||Within the embankment the sea water is stored (illustration missing)|
|10||就海引潮圖||Diverting the tidewater (illustration missing)|
|11||築獲海岸圖||Protecting the sea shore by dyking|
|12||車接海潮圖||Connecting to the tidewater with water-lifting machines|
|13||疏浚潮溝圖||Dredging the tide [water] ditches (illustration missing)|
|14||開闢攤場圖||The opening up of the spreading place|
|15||車水耕平圖||Lifting the water and ploughing evenly (illustration missing)|
|16||敲泥拾草圖||Breaking up clods and clearing weeds|
|17||海潮浸灌圖||Flooding and irrigating with the tidewater|
|18||削土取平圖||Parting the earth and levelling it|
|19||棹水潑水圖||Lifting water with a bucket and sprinkling it|
|20||擔灰攤晒圖||Carrying the ashes and spreading them for exposure|
|21||篠灰取匀圖||Levelling the ashes with dwarf-bamboo brushes|
|22||篩水晒灰圖||Sprinkling water and exposing the ashes|
|23||扒掃聚灰圖||Collecting the ashes by paring and sweeping|
|24||擔灰入淋圖||Carrying the ashes and pouring them into the leaching basin|
|25||淋灰取滷圖||Leaching the ashes and extracting the brine|
|26||滷船鹽𦨣圖||Brine boats and salt boats|
|27||打滷入船圖||Loading the brine into the boats|
|28||擔載運滷圖||Carrying or shipping the brine|
|29||打滷入團圖||Unloading the brine and conveying it into the unit|
|30||樵斫柴薪圖||Gathering and chopping fuel|
|31||束縛柴薪圖||Bundling up the fuel|
|32||砍斫柴玍圖||Cutting fuel sprouts|
|33||塌車𨎿車圖||Sledges and wheeled carts|
|34||人車運柴圖||Transporting the fuel by sledges and carriers|
|35||𨎿車運柴圖||Transporting the fuel by wheeled carts|
|36||鐡盤模様圖||The design of the iron pan|
|37||鑄造鐵柈圖||Casting the iron pan|
|38||砌柱承柈圖||Building the brock props which support the pan|
|39||排湊盤面圖||Arranging and joining the pan surface|
|40||煉打草灰圖||Refining straw and ashes by beating|
|41||装泥柈縫圖||Plastering the seams of the iron pan|
|42||上滷煎鹽圖||Adding the brine and boiling it to salt|
|43||撈晒撩鹽圖||Straining and removing salt|
|44||乾柈起鹽圖||Recovery of salt from the dry pan|
|45||出扒生灰圖||Raking out the living ashes|
|46||日収散鹽圖||The loose salt is collected daily|
|47||起運散鹽圖||Transporting the loose salt|