An extremely rare English sea chart of the Gulf of Siam, Thailand, Malaysia and a portion of the Straits of Malaca, Cambodia and Vietnam. It was published in William Herbert’s ‘New Directory for the East Indies.’ Herbert (1718-95) travelled to India in about 1748 as a purser’s clerk. Returning in the early 1750s, he began a map and print shop on London Bridge, and in 1758, with the encouragement of the East India Company, he introduced a new pilot guide, ‘The New Directory for the East Indies.’ Herbert gathered superior sources than those used in Mount & Page’s The Third Book, consulting such works as Mannevillette’s ‘Neptune Oriental’, as well as the navigator William Nicholson and the mapmaker Samuel Dunn.

The map details inland rivers also such as the Chao Phraya River, charted through ‘Siam’ (Ayutthaya). Cambodia and Vietnam and the Mekong river appear prominently. It also clearly identifies the Paracel Islands. There are a number of soundings, along with two profile views in the lower left corner. The northeastern part of Borneo is also illustrated lower right. NMM pp.414-5 no. 25; Shirley (2004) M.Herb 1a 25.