1. Ordnance survey Maps

2. The Basics
Ordnance Survey Maps in Ireland are produced by the OSi (Ordnance Survey of Ireland)
The maps we use mostly are drawn to a scale of 1:50,000. This means that 1cm measured on a map is equal to 50,000cm on the ground (ie: 500m, which is 0.5 km)
Put another way, every 2cm measured on one of these maps is equal to 1 km on the ground.
Maps showing very large areas (eg: A map of Europe) have scales of approx 1:500,000.
Maps of small areas (like part of a town) would have scales like 1:8,000
By knowing the scale the map is drawn to it allows you to measure distances.

3. Map Scale

4. Straight Line distance
This involves calculating the distance between 2 points on a map in a straight line.
This done by:
Marking the 2 points on your map.
Taking a strip of paper and laying it along the distance between the 2 points and marking them on the paper.
Then placing the paper on the scale and reading off the measurement
Give your answer in Kilometres

6. Reading your Result

7. Curved Line Distance
This involves measuring the distance on a map between 2 points, along a curved feature like a Road.
The process is the same as for a Straight Line distance but just involves more steps.
Every time you come to a bend in the road you must carefully rotate the paper and mark it each time until you get to the end point.
Then read to off on your scale, only paying attention to the first and last mark on your paper

8. STEP ONE
STEP TWO
STEP THREE

10. Map Symbols Features on a map are shown using symbols.
These are found on the Legend Page on the back of a map.
They are divided into different sections.
All the symbols on a map are explained in the Legend.
They include symbols for Garda Stations, Tourist Offices, Different types of roads, Historic Sites, etc

12. Giving a Grid Reference
Every map of a part of Ireland has a place on the National Grid. This is represented by a Letter. This is called the SUB-ZONE LETTER

14. As well as the sub-zone letter each map contains 2 sets of numbers.
They are called :
EASTINGS and
NORTHINGS.
Eastings are the numbers that run along the top and bottom of the map.
Northings are the numbers that run up either side of the map.

15. An easy way to remember which is which is to remember that Eastings are the numbers going Eastwards across the map
And Northings are the numbers going North, up the side of the map.

16. EASTINGS N O R T H I G S
SUBZONE
LETTER

17. A Grid Reference is given by combining these 3 things in the following order:
LETTER
EASTING
NORTHING

18. A 4-figure Grid Reference

20. A 6-figure Grid Reference
This is a more exact way of giving the location of a small item on a map like a Post Office, a Church, a School, etc
It works like a 4-figure reference except you now create imaginary decimal places.
FOR EXAMPLE:

22. The 6-figure Grid Reference for this Golf Course is…