A reference card or Romer is a device for increasing the accuracy when reading a grid reference from a map.

Design and use

Made from transparent plastic, paper or other materials, reference cards are found on most baseplate compasses. Essentially, they are a specially marked-out ruler which matches the scale of the map in use. The scales are laid out in reverse, such that by lining up the numbers given in the grid reference with the gridlines for the square in question, the corner of the Romer lies on the location the grid reference of which is being read. Some transparent versions have a small hole at the origin when this is not at the corner of the reference card. This allows access to the map such that the location could be marked with a pencil if using the reference card in reverse having been given a grid reference to start with. They are used in many types of

land navigation Land navigation is the discipline of following a route through unfamiliar terrain on foot or by vehicle, using maps with reference to terrain, a compass, and other navigational tools. It is distinguished from travel by traditional groups, such as ...

and map reading, to give a more accurate grid reference than one just estimated by eye from the grid lines on the map. While Romers of various designs are available commercially, they can easily be made by hand, by using a computer, or by finding a website with instructions.

History

Invented in 1915 by Temporary Lieutenant (later Captain) Carrol Romer, M.C., R.E. (1883–1951), then "Maps", First Army: i.e. OC Maps and Printing Section, such reference cards were widely used by the

British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurk ...

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

and after, being described in a Maps GHQ booklet ''Maps and Artillery Boards'' in December 1916. The name 'Romer' seems only to have been used officially from 1929. and A version was later developed for car navigational rallies by car rally partners Eric Gardner and John Cridford during the early 1950s, the 'Garford Romer' was available for both

imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imperial, Nebraska * Imperial, Pennsylvania * Imperial, Texa ...

and

metric Metric or metrical may refer to: * Metric system, an internationally adopted decimal system of measurement * An adjective indicating relation to measurement in general, or a noun describing a specific type of measurement Mathematics In mathema ...

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maps and is still sold today. Although a registered design when it was first made and sold it was and still is much copied.

References

{{Reflist, 2 Cartography Navigation Military cartography Road rallying

Design and use

History

See also

References