The two sheets illustrate the whole of the South American continent. It records remarkable internal detail but also records areas with a lack of information. One small inset displays the Galapagos Islands. In 1848 Johnston published the ‘Physical Atlas’, the ‘first British atlas to give a synoptic view of physical geography’ (Tooley). These maps appeared in the ‘General Atlas’ published c.1862 by William Blackwood & Sons of Edinburgh and London.

The successful firm of W. & A. K. Johnston was founded by Sir William Johnston (1802-88) and was based in Edinburgh from 1825. The following year he was joined by his brother Alexander Keith Johnston (1804‐1871). They were an active firm of mapmakers, engravers, lithographers, and publishers. Provenance: private collection of Juan and Peggy Rada. Shirley (2000) ‘Berghaus and Johnston: Pioneers of the Thematic Atlas’, in IMCoS Journal no. 83 pp. 31-5; Smith, David. (2000). ‘The Business of ‘W. & A. K. Johnston’ 1826-1901′, in IMCoS Journal no. 82 pp. 9-19; Smith, David. (2001). ‘The Cartography of ‘W. & A. K. Johnston’ 1826-1901′, in IMCoS Journal no. 86 pp. 5-16; Tooley’s Dictionary (1999-2004); Worms & Baynton-Williams (2011).