representative fraction statement of scale grid reference easting northing
cardinal point
straight-line distance curved-line distance regular area irregular area
Ordnance Survey Ireland (OSI)
Maps are drawings of the earth’s surface that show how things are related to each other by distance, direction and size. Ordnance Survey Ireland (OSI) draws and publishes 75 of these maps covering the entire landscape of Ireland as part of their Discovery Series.
The National Grid
The National Grid is used to give the location of places on Ordnance Survey (OS) maps of Ireland. It consists of 25 squares called sub-zones which cover the whole country and some of its sea areas. Each sub-zone measures 100 km in length and 100 km in width and is identified by a letter of the alphabet from A to Z. As there are 25 sub-zones, one letter of the alphabet is not used – the letter I. Sub-zone letters are illustrated in a blue colour (Fig. 12.1(a)).
A B C D E F G H
J
L M NO P Q R S T
LEARNING INTENTIONS
By the end of this chapter I will be able to: z z
Syllabus Links: 3
use Ordnance Survey map reading skills to get location, direction, distance and area; zzdraw and interpret sketch maps and cross-sections; zz
recognise and interpret symbols and colours relating to the physical, human and economic landscape.
