Map of a Nation by Rachel Hewitt: book review

Map of a Nation: A Biography of the Ordnance Survey (2010) is the history and circumstances of how Great Britain was mapped, inch by inch. Hewitt begins in the Scottish Highlands with David Watson (photo below) in 1746 frustrated with limited information about the geography and exascerbated by inadequate maps. It covers the period 1747-1870 with ‘digressions and distractions’ and conflicts about place names, such that the first ordnance of the entire land, with stops and starts, took 79 years to complete.

Hewitt writes of the scientists, mathematicians, toolmakers, leaders, soldiers, walkers, and artists – and of the hostilities and friendships along the way, not just between the surveyors, but also between England and France. The French were ahead of the British in terms of surveying, and in 1783 a team of French astronomers approached the Royal Society of Britain to instigate a measurement between the observatories in Paris and Greenwich, hence the book looks inward to the whole of Britain, and outward across the channel.

In 1707 the Act of Union officially united Scotland and England into Great Britain, and there was an ordnance office (primarily for military purposes) since the late 14th century.

In 1747 William Roy began mapping the Scottish Highlands under Watson’s management – living in a tent on a mountain – and finished in 1752. Then the team surveyed the Scottish Lowlands, finishing by 1755, although the maps had no legend to explain their ‘vocabulary of symbols’ and were not ‘a uniformly accurate image of the landscape’ with a ‘proliferation of errors.’ Watson was asked to conduct a reconnaissance of sections of England’s south coast, but died in 1761.

In 1766 Roy wrote to King George III with the suggestion to map the whole of the British Islands over 6-8 years, but was rejected. He was also enthusiastic about working with the French to triangulate the exact latitude and longitude of the Greenwich and Paris observatories, despite much criticism – and despite years of feuding and wars between the two countries. But from the 1790s Robert Clifford was acquainted with French surveying methods and Roy’s dream commenced under William Mudge’s management. Then came the Napoleonic Wars and the introduction of John Macadam’s new gravel and tar roads (tarmac) which brought ‘annoying tourists’ to the surveying sites. And some locals feared that surveying meant an imminent change to taxes or the division of land and became most unfriendly.

By 1800 two Acts of Union joined Ireland to Wales and England into the United Kingdom, and therefore Ireland was also surveyed, commencing in 1824 and taking almost 20 years.

The book also covers the history of the instruments used in surveying: from the use of beacons, lamps, limelight, and fires, to the plane table and an alidade, to a surveyor’s wheel, to a chain and circumferentor, theodolite, heliotrope, and barometers. ‘Mountains were particularly tricky to map’ and barometers were used to measure air pressure to calculate a mountain’s altitude – before contouring and toponymic innovations were developed. There is a discussion of the lunar-distance chronometer method of overcoming the longitude problem, and the introduction of the ‘one inch to a mile’ scale.

It’s an epic book, commencing with a back-and-forth timeline before eventually becoming more linear. With anecdotes and amusing insights into the lives of surveyors, it is not a dry tedious account, but rather, it is quite a pleasure to read. Included in my version are black and white illustrations and colour photographs.

MARTINA NICOLLS is the author of:- The Shortness of Life: A Mongolian Lament (2015), Liberia’s Deadest Ends (2012), Bardot’s Comet (2011), Kashmir on a Knife-Edge (2010) and The Sudan Curse (2009).