John Hamilton Mooreÿ(1738-1807), To His Royal Highness Prince William Henry this Chart of the British Channel, Is most Humbly dedicated by his most Obedient and Dutiful Servant John Hamilton Moore, London, marked "Sold by Mr. Moore in London: Mr. E Smith in Liverpool and Mr. Edgworth in Bristol" and "London, Published as the Act directs June 27th 1786 by John Hamilton Moore Tower Hill", signed "James Severs" verso, engraving on laid paper, 31-1/4 x 71 in.; unframedNote: This chart of the Indian Ocean along the coasts of Mozambique, Arabia, and Zanzibar, with an inset of the harbor of Bombay is one of five charts in the Sever Collection known as a ?Blueback Chart? because of the blue paper backing that was pasted on the back to strengthen it. Bluebacks were drafted, printed, and sold by private London publishers and were preferred by merchant ship captains worldwide over those produced for the Admiralty because they were designed to meet the needs of specific routes. Often both the departure and the destination were incorporated within a single map and they generally contained a number of inset maps to assist with navigation into various ports along the way. This chart contains numerous coastal elevations and the following inset maps: 1. Spithead/Isle of Wight, 2. The Downs, 3. Plymouth, 4. Dartmouth, 5. Falmouth.Although blueback charts were often more expensive than charts produced by the British Admiralty, the cost was offset by the need for fewer of them due to the inclusion of the inset maps. Moore?s chart of the English Channel was one of his most successful charts and was needed for almost all merchant vessels. Moore claimed to have sold upwards of 5,000 copies of this chart.John Hamilton Moore (1738-1807) was a well known teacher of navigation. He was born in Edinburgh, educated in Ireland, and subsequently joined the Royal Navy at Plymouth. In about 1770, Moore established a Nautical Academy in Brentford, Middlesex, and in 1772 he publishedÿThe New Practical Navigator and Daily Assistant. Later he established himself at 127 Minories, near Tower Hill, where he taught navigation and carried on his business of selling maps and nautical instruments.Click here to read about this important American maritime collection from the Sever family and to view additional items from this collection. - Provenance: Captain James N. Sever (1761-1845), Captain USS Congress; by descent in family several vertical creases from being rolled, one 1 inch tear in the upper right margin and a few small losses in the upper left margin, minor wear to edges, scattered small holes/losses throughout, scattered creasing and staining throughout