THORNTON, J. - A large draught of the North part of CHINA. Shewing all the passages and chanells into the harbour of CHUSAN. / To the honourable the court of mannagers for the UNITED TRADE to the EAST INDIES.

A very fine sea chart of China's Zhejiang Province, from the celebrated Third Book of 'The English Pilot'
This elegant and large chart captures China's modern day Zhejiang province. Located on the East China sea, just below the Yangtze Delta with Shanghai, this region was of major interest to European traders during the eighteenth-century. It features the major port of Zhousan (Chusan), and was the location of the entrance of the Grand Canal of China. The canal, construction of which began in the 5th-century B.C., was then the oldest and longest man-made waterway in the world, which allowed barges to travel hundreds to Beijing.
In 1671, the London cartographer John Seller (fl.1664-97) commenced work on The English Pilot, a work that intended to challenge Dutch hegemony in the sea atlas market. Intended to be published in four books covering different regions of the globe, Seller published an uncompleted book on 'Oriental navigation' in 1675. Unable to continue this Herculean endeavour, Seller sold his rights to John Thornton, the official hydrographer to the English East India Company. Thornton took up the project with great fervour, publishing his first editions in 1689. Thornton did not publish his first edition of the Third Book, detailing navigation in the East Indies, until 1703. While Thornton largely based his charts on those of earlier Dutch cartographers, most notably those found in Pieter Goos' Zee-Spiegel and Lucas Janz Waghenaer's Mariner's Mirror, The English Pilot proved to be enormously popular. When John Thornton died in 1708, his brother Samuel took over the business and added to and modified existing charts. All four books were produced in editions until the 1760s, the Third Book ran into twelve editions up to 1761.
The project succeeded in giving the English dominance in the sea chart market as the eighteenth-century progressed. John Thornton collaborated with Seller in many of his publications but was also an hydrographer in his own right. Thornton was a skilled engraver and played an important part in the production of the various edition's of Seller's Atlas Maritimus, and later issued his own version.