John Rocque's maps of London were published in 1746. A French-born British surveyor and cartographer,
John Rocque produced two maps of
London and the surrounding area. The better known of these, depicted here, is a 24-sheet map of the
City of London and the surrounding area, surveyed by Rocque and engraved by
John Pine and titled
A Plan of the Cities of London and Westminster, and Borough of Southwark. Rocque combined two surveying techniques: he made a ground-level survey with a compass and a physical metal chain – the unit of length also being the
chain.
Compass bearings were taken of the lines measured. He also created a
triangulation network over the entire area to be covered by taking readings from church towers and similar high places using a
theodolite made by
Jonathan Sisson (the inventor of the telescopic-sighted theodolite) to measure the observed angle between two other prominent locations. The process was repeated from point to point. This image depicts all 24 sheets of Rocque's map.
Map credit: John Rocque and John Pine
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