This chart by a Captain Robert Williamson of Liverpool met that demand for accurate charts. The Science Museum holds a trade card for him and offers trading dates between 1761 and 1769. It details the extensive range of goods sold; books, maps, prints, navigating instruments, spectacles, and musical instruments. Arkle stated that he is likely one of the earliest merchants of American cotton, having sold by the candle at auction nine bags on 7 September 1756. Selling ‘by the candle’ was a practice where usually a one-inch candle was lit, and the goods were open for bids whilst lit. As soon as the candle went out, the auction closed. He was the publisher of ‘The Liverpool Memorandum Book’, and ‘Williamson’s Liverpool Advertiser and Mercantile Register’ from 1756-69, which later became the ‘Liverpool Times’. Arkle records the last use of his name in this year, 1767, the business being continued by his widow Alice until 1773.

The chart itself illustrates a shipwreck at Dundrum Bay in Ireland. A legend nearby identifies it as his own, ‘Author Ship Wreck’t Jan. 21. 1748 occasioned by the Errors of the Drafts then Extant’. The Directions state for this bay, ‘hitherto a very dangerous Bay, occasioned by the Errors of all former Charts extant … The Author was shipwreck’d here in 1748, which first laid the foundation of this Chart.’ It also illustrates the battle off the Isle of Man in 1760 of Francois Thurot. The battle in which he died ended his reign of terror over the British during the Seven Years War.

The chart extends from the Bristol Channel in the south to Glasgow in the north and the whole of the eastern seaboard of Ireland from Waterford to Rahlin Island in the north. A total of 21 inset charts of harbour are found including detailed ones of Dublin Bay, Liverpool, and Glasgow, the latter all provided with tide tables. Tide data is provided from the invention of Edmund Halley who was the first to use roman numerals to indicate how many hours from a central tide table high tide was in any place. Halley first introduced the method on his three-sheet chart of the English Channel, 1702 [https://www.caburdenraremaps.com/map/a-large-chart-of-the-channell-between-england-and-france-done-from-the-newest-and/]. It records all the usual features including soundings, drying and submerged banks, anchorages and is illustrated with several ships.

The map is dedicated to Edward Augustus Duke of York, brother to George III, approved and certified by John Pownall, principal secretary of the Board of Trade and Plantations, and younger brother of Thomas Pownall, one time Governor of Massachusetts 1757-60, and member of Parliament from 1767-80. The chart is engraved by Edward Thorowgood (fl.1749-68) and James Larken (1732-74) at the scale of 2 centimetres per English or French League. That translates to about 3.81 nautical miles per inch.

The accompanying ‘Directions for Sailing into the British and St. George’s Channels’ in three folio pages are duplicated at the front and back, enabling easier use with the two folding three-sheet charts. A statement at the end records that the chart was examined by the Admiralty and that he was ordered to compare them with the manuscript charts of Murdoch McKenzie, chartmaker to the Admiralty. Front and back are supplied with no less than four blank leaves for note taking.

The work was sold at several London premises including those of Thomas Jefferys, Robert Sayer, Carington Bowles, Henry Parker, Edward Thorowgood, Heny Gregory, John Gilbert, along with of course Robert Williamson himself in Liverpool. Thomas Jefferys himself was going through a torrid time as the London Gazette announced in their issue for 1-4 November 1766 that ‘a Commission of Bankrupt is awarded and issued forth against Thomas Jefferys, of Saint Martin’s Lane …’ and that he was required to ‘make a full Discovery and Disclosure of his Estate and Effects’. It seems that quite quickly his affairs were put back in order due to the generosity of some friends, one of whom was Robert Sayer. An engraved copperplate script letter signed by Jefferys and dated 17 January 1767, survives in the Ayer Collection, at the Newberry Library, Chicago. It states, ‘that by a train of unforeseen Accidents … my affairs were brought into so much Disorder, that I was lately obliged to become a Bankrupt’.

There are only four recorded examples of the chart surviving. Those at the British Library (Maps K.MAR.III.36.1) and the National Library of Wales (Hydrographic Charts Map 2224) consist of the chart only. The Bibliotheque Nationale, Paris, hold two examples (Cartes et plans, GESH18PF25DIV1P4), one is loose only again but with accompanying text and the D’Anville Collection (01916 B) example is with the text in blue paper wrappers. This is the only example bound and the only example with text in the British Isles. Provenance: private English collection for about 40 years. Arkle, A. H. (1916) ‘Early Liverpool Printers’ pp. 78-9; Evans (1969) no. 108; Tooley’s Dictionary (1999-2004); Worms & Baynton-Williams (2011).