Everyone knows of the maps produced by Ordnance Survey, but what of its origins? What was it that fueled the fire to make OS a world leader in surveying landscapes?

Ordnance Survey

Silva Expedition 4 Compass
Silva Expedition 4 Compass

The Jacobite Rising

The Ordnance Survey (OS) is the official national mapping agency of Great Britain. The first ordnance survey undertaken was of the Scottish highlands between 1747 and 1755. This task was executed following the Jacobite rising of 1745 – 1746 to elucidate areas in the Scottish countryside where Jacobite dissenters could be evading detection. The map was completed one inch to 1000 yards (1:36,000) under the supervision of Col David Watson and more notably due to the participation of William Roy (1726-90.)

William Roy was a Scottish engineer, surveyor, and antiquarian who maintained an illustrious career in the Royal Engineers (RE) throughout his adult life. Roy displayed a particular interest in the creation of an official survey of Britain by putting forward multiple proposals that were all denied due to financial reasons. Roy was commissioned to geodesically determine the distance between the observatories in Paris and Greenwich. Requiring the creation of the most precise theodolite (measures angles horizontally and vertically), Roy settled the long-lived dispute of the observatory’s relative distances.

Ordnance Survey

It was on the 21st of June 1791 that the board of ordnance purchased a second theodolite and the Ordnance Survey was officially founded. The ordnance survey was also established due to the rising threat of a French invasion of England during this time. It was determined that without adequately surveyed maps of England’s terrain, soldiers could not be positioned effectively. Up to thirty men were hired to undertake and monitor the operations. In 1784-6 a six-inches-to-one-mile (1:10,560) survey of Plymouth was carried out and overseen by The third Duke of Richmond, then Master-General of the Ordnance. By 1801 the first map of Kent had been produced after surveying the area in the late 1780s. Both of these areas were of great military interest and remained the sole surveyed and mapped areas until sights turned towards mapping the entire UK in 1795.

The French Revolutionary Wars

The idea to map the entirety of the UK caught on due to the war in France (1793.) It was decided that more surveys and maps would be needed for protection in the ever-increasing event of a French invasion. Large swathes of South and Midland England had been mapped by the end of the war in 1815 on a predominantly two-inch (1:31,680) scale. It was following this period that certain ordnance surveys were published before being retracted from sale due to security reasons.

From 1821 to 1886 there were a few hindrances to the evolution of surveying work. In 1820 Captain Thomas Colby was put in charge of surveying work. Colby discovered that much of the previous work had not been to standard and needed to be reviewed. Following ten years spent remapping and checking certain areas, surveying sights turned to Ireland where land was to be mapped for taxation reasons. During this time, however, Colby made significant improvements to the data collection done during the surveying by recording place names and reorganising the map-making process to produce clear and accurate plans.

Scawfell Pike

It is noted that this system led to some notable errors such as when recording the name of Scafell and Scafell pike which was originally spelt as Scawfell. The erroneous name has stuck to this day.

Colby undertook the operation of surveying much as a military commander might by building a rapport among the men on his team as he travelled around the country with them. It is recorded that not only would Colby set up camps with his men but would also throw celebrations and feasts upon the termination of surveying a site. In the late 19th century following through to the early 20th century, there was a good deal of controversy surrounding the map scales that would be appropriate for surveying of villages, towns, cities, and open spaces. It was decided that the scales would be set as 1:1250s, 1:2500s, and 1:10,560s after the Second World War.

The Ordnance Survey historical maps here are very interesting.

World Wars

By the time the world war broke out in 1914, there was a series of surveys taking place in both France and Belgium conducted by the ordnance survey. As before, these maps were created to improve soldier placement throughout the land. The maps are cited as vastly improving military tactics by allowing generals an enhanced knowledge over the landscape, thus leading to an increase in the accuracy of shooting and shielding.

The development of Ordnance survey maps continued into World War II where it became possible to digitally image vast swathes of land from a plane. This led to the production of maps of cities and entire countries such as Antwerp, Brussels, Italy, and South Africa. Naturally, these maps allowed for generals to garner a better knowledge over the land they were covering on missions.

Black Crag trig pillar
Black Crag trig pillar

Though the Southampton Ordnance survey offices were destroyed during the blitz, surveying of European cities and towns continued throughout the war. The vast and tireless surveying conducted by draughtsmen during this time is evidenced by the 6,500 trig (triangulation) points that are found throughout the UK and various parts of Europe.

Digital Mapping

In 1995, the UK became the first country to compile a programme of large-scale electronic mapping after the Ordnance survey digitised 230,000 maps. The national mapping agency of Britain has continued catering to a more connected and digitally active populace. Location data and geographic information (GI) are now an integral part of how Ordnance Survey is conducted.

OS maps are now improved by over-laying high-definition images on existing maps. These images are constantly being captured by both the organisation’s external and flying units. This process leads to instant updates of the maps within their digital databases ensuring the sharpest accuracy possible. Britain holds its place as a world-leading geospatial nation through its Global Navigation Satellite System (GNSS) base stations. The mapping agency has also started exploring the use of unmanned aerial vehicles to capture highly detailed features of the landscape at street level.

Location data currently plays an important role in the growth and sustainment of the business industry and is expected to fuel the power of the digital economy in the future.

Into The Countryside with Ordnance Survey

Map reading course at Honister
Map reading course at Honister

Now of course, we plan our routes online before setting foot in the countryside. We use GPS like the SatMap Active 20 with digital maps to follow the route when we’re out in the field (or Ordnance Survey paper maps with a Silva Expedition 4 if you’re old-school like us Mountain Leaders). I open my OS maps app on my phone every day, out or not.

Ordnance Survey is part of our lives. Hope you found this interesting.

Why Not Read…

OS Maps Online
OS Maps Online

OS Maps Online

The Ordnance Survey Maps Online gives you the freedom to plan all of your routes on your PC before you go anywhere, then you can access it all on your phone when you’re on the fells.

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