I was back in North Uist and Harris this month, and stumbled over another Georgian scientist connected with the area, the main focus of the geology exhibition in Taigh Chearsabhagh in Lochmaddy. Although the exhibition covered work in the islands up to the present day, it was put on to mark 200 years since the publication of MacCulloch’s Description of the Western Islands of Scotland in 1819.
Unlike William MacGillivray, whose book I was reading when I was there last year, John MacCulloch had no native connection to the area – he came from a Scottish family, but was born at the home of his mother’s family in Guernsey. He studied medicine at the University of Edinburgh, but returned to work for the army in London, first as an assistant surgeon, and then as a chemist. It was the Army Board of Ordnance which first sent him into the highlands of Scotland in 1809, in search of stone which could be used to grind gunpowder without sparking – the usual sources having been cut off by the Napoleonic wars.
He later worked as geologist for the Trigonometrical Survey, the basis of the first Ordnance Survey maps, and his work in Scotland for the army seems to have interested him, as well as showing him how much was still to be done there – leading to the first geological study of the Western Isles, and the first serious description of Lewisian Gneiss, the oldest rock in Britain. He kept on working in Scotland, preparing the first geological map of the country between 1826 and 1834, but was unfortunately killed in an accident before it was published.