I recently visited the Geological Society in central London as part of a tour organised by the History of Geology Group and the Charles Close Society for the Study of Ordnance Survey Maps. The highlight of the visit was a display of maps selected from the Geological Society’s library and archive collections. I enjoyed it so much that it inspired me to look at some 19th century geological maps from our own collections for today’s blog post.
Although we do not hold any discrete sets or collections of geological maps here at The National Archives, we do have quite a lot of maps that include some geological information. 1 Some of these are in rather unexpected places among the records. For instance, I was initially rather surprised to find a geological map among railway records. 2 On reflection, though, I realised that this made sense: geological information can be extremely valuable when planning new railway lines.
Another of our geological maps forms part of one of several 19th century proposals to build a Channel Tunnel between southern England and northern France. 3 It dates from about 1881 and comes from Foreign Office correspondence.
Some Colonial Office records include maps relating to the geology of former British Colonies. The example below shows part of British Honduras (now Belize) in Central America. 4
The final map I want to look at in today’s post is my favourite of the four. It comes from the War Office’s map collection and shows the Isle of Wight, off the south coast of England, and adjacent parts of the mainland. 5 It is a Geological Survey map, consisting of a topographical 6 Ordnance Survey map, re-published with geological information added.
The Geological Survey was formally set up in 1835 to produce official British geological mapping. 7 Originally, it was a department within the Ordnance Survey, but by the time this map was published in 1856, a separate organisation the Geological Survey of Great Britain and Ireland – had been established. This was the forerunner of today’s British Geological Survey.
Geological Survey maps like this one are of extremely high quality. 8 Both the topographical base maps and the added geological information were produced with the best available data and to the highest technical standards possible in the mid 19th century. The map was engraved and printed in black ink, with the colouring added neatly by hand. Colour printing techniques in the 1850s were not advanced enough to make printing a map like this in colour viable.
Access to accurate mapping and other geological data can be vitally important to a wide range of organisations, from oil companies to universities, and to people working in a variety of professions, from civil engineering to environmental science. Yet, although geological maps are primarily practical tools, even those (like me) who have little knowledge of geology can still appreciate them for their appearance. For most people, it is their beautiful colours that make geological maps such fascinating objects.
It is often said that the best maps strike a perfect balance between science and art. We have many maps at The National Archives that illustrate the truth of this observation but, to my mind, geological maps offer some of the clearest examples.
- 1. Describing our holdings of maps as a ‘collection’ is a useful shorthand but really something of a misnomer: our records include both separate collections of maps and maps that are intermingled with textual records. ^
- 2. RAIL 1031/13 ^
- 3. MFQ 1/946/3 (map extracted from FO 27/2901) ^
- 4. MFQ 1/196/9 (map extracted from CO 123/180) ^
- 5. MPHH 1/439/1 (originally WO 78/2153/1) ^
- 6. A topographical map is one that depicts natural and artificial features of the landscape. Most ordinary, general-purpose maps are topographical maps. ^
- 7. See this page on the British Geological Survey website for more information about 19th century official geological mapping. ^
- 8. You can see this for yourself by browsing some more historical Geological Survey maps on the British Geological Survey website. ^