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William Smith Map FAQs

"The Map that Changed the World"

Q - Was William Smith a member of the Geological Society?

A - No, he was never elected. However he was awarded the very first Wollaston Medal by the Society in 1831.

Q - How many maps did he make?

A - We don't know because the unnumbered series of 1815 maps is of unknown length. There may have been as many as 400 made and it is thought that there may be between 40 and 50 still in existence

Q - What is the number of the Geological Society's Smith map. Is it No. 1?

A - No, it is not No. 1. No identifying number has been found on the map, but it is a late edition (after 1836). The serial number, when it exists, appears at the bottom of Sheet VI, below the geological section.

Q - How can you tell which edition it is if there is no number?

A - The best clue is to look at the Isle of Wight. The outline of the Cretaceous strata changes on each edition as more information on the geology of the island became available. Also the Coral Rag does not appear on the earliest maps, then appears first in southern England, but by later editions has been extended into Yorkshire.

Q - How long has the map been hanging on the wall?

A - There has been a framed copy in the Society for at least 100 years. In 1932 it was said to be quite faded and another copy was framed to replace it in around 1934. The curtains now cover the map to prevent undue damage from the light.

Q - Can I buy a copy of the map?

A - Originals occasionally come on the market at auction or in antiquarian book dealers' catalogues. The British Geological Survey have published a half-scale facsimile, which is available from the Geological Society's Burlington House Bookshop or from the British Geological Survey's Online Bookshop.  His later 1820 map is also available as a facsimile reprint from the BGS.

Q - How much would it cost to buy an original?

A - A dealer recently (June 2003) sold one for £55,000 and Christies had another in their auction catalogue (in poor condition) with a ‘reserve price' of around £25,000.

Q - Are there any websites I can visit to find out more about William Smith?

A - Perhaps the best sites to visit are the University of Oxford's William Smith Online, the British Geological Survey's William Smith page and the University of New Hampshire's William "Stata" Smith on the Web .

Q - Why isn't it called a “Geological Map?”

A - Smith would have known the word, but remember not many other people did in 1815. Smith was trying to sell this map to non-specialists, who would definitely never have heard of it. At this date, Smith still called himself an engineer or mineral surveyor. The Society's 1819 Map had other imperatives however – to mark out a new science and to establish the Society as being in charge of it. Theirs was a political badging exercise, so using the word “Geological” was very important to them – and it appears in large gothic letters right at the top.

Q - Were they all coloured by hand?

A - The colour was applied to a printed base by hand using watercolours. Some colourists were better than others. Each one was made for a customer as required, which is why the stratigraphy shown on the map evolves over time – the later maps have more detail. The base map, specially commissioned and very spare of topographic data (no shading for hills and valleys) was made by John Cary, engraver, who worked with Smith on many projects.

Q - Why is the colour graded?

A - Another of Smith's pieces of visual language – never taken up because it was beyond the printing technology of the 19th Century. He coloured the bases of rock units darker than the rest – so you can always tell at any point, without referring to the key or any other symbols, which way the rocks are getting younger (“younging”). And once you have your eye in, you can then use that information to tell which structures are upfolds (old rocks in the middle) and which are downfolds (young rocks in the middle). Can you identify one example of each on the south East coast of England? (A. The Hampshire Basin, syncline (downfold) and the Weald, anticline (upfold).

Q - What's that floating in “The German Ocean”?

A - That's another thing that Smith invented – a schematic section across the country from Cardigan Bay to the Thames, showing the strata leaning against – dipping eastwards from – the massifs of folded, slaty rocks in the west. This was how Smith viewed the structure of Britain.

Q - Is Smith geology's answer to Leonardo da Vinci?

A - There could be something in this! Smith not only discovered the two scientific principles underlying this and all subsequent stratigraphic maps, and then applied those principles single-handed to almost the entire country – a feat that has never been equalled. He also had to invent a whole new visual language to display the structure that he was laying bare. So, just as Leonardo invented two visual languages we take for granted today, namely technical drawing and anatomical (dissection) drawing, Smith invented the visual language of the geological map that today is so familiar that it never occurs to anyone that it had to be invented.


Q - It is the Bicentenary of the publication of the Map in 2015.  Is this being celebrated?

A - A number of events are planned across the country.  Details of these are listed on our website.

  • Compiled by Wendy Cawthorne and Ted Nield, Geological Society of London. Revised June 2014

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