The Charles Close Society for the study of Ordnance Survey maps

Digital Images Archive

Quarter-inch (1:253,440) map of (central) Ireland composite with military grid

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65. In about 1930, Captain James Flynn and Lieut Hugh O’Neill, members of the Topographical Section, General Staff of the Irish Republic, prepared a 'Memorandum on the steps involved in the production of a 1:20,000 map of Ireland from the existing large-scale Ordnance Survey plans'. The result was a map laid out in 513 sheets. Of these only six were published, four in 1934-5 and these four again, together with two more, in 1939-40 in a revised specification. The origin of the map was at 53°30' N, 8° W, the same as that in use on Ordnance Survey national maps of Ireland. A new metric grid was adopted, calculated from a false origin 189,000 metres west and 234,000 metres south of the true origin. It was overprinted in red at 1 km intervals. The same grid, at 10 km intervals, was overprinted on the sixteen sheet quarter-inch map of Ireland, for use of Air Corps and artillery training. The one set of these gridded quarter-inch maps known were assembled into three composite sheets covering the north, centre and south of the country, leaving only the original sheet 14 separate. At present the southern composite has not been recorded.

From a copy in a private collection