The Ordnance Survey of Northern Ireland: An Outline of its History and Present Mapping Tasks

Abstract

This explains the formation of the Ordnance Survey of Northern Ireland as a separate institution in 1921, when it took over the map series which until that time had been part of the Ordnance Survey (U. K.) responsibility. As happened with many mapping organisations, replanning and reorganisation took place after 1945; this included a triangulation for Northern Ireland to provide a basis for a new Irt"sh Grid, and the introduction of the 1:1250 scale for major urban areas.

The technical problems of reproduction and revision are then considered, and details given for each of the main series.