Map Collections at UCD and on the Web: Scales, Symbols, Coordinates & Indexes
Scales & Series
The following are examples of maps of differing scale. Use this composite to compare scales.
Mapping at 1:1000 (approx. 5" to 1 mile), see this sample map, began at the end of the 1960s for Dublin, Cork, Galway, Limerick and Waterford cities. This has extended over the years and this scale is now available for urban areas with a population in excess of 1,500 (approx). Revisions are now running at about every 1-2 years.
The 1:2500 scale comprises maps from both the older 25" series and the newer 1:2500 series. The old 25" series covers all areas of the country except for remote rural regions. For more information about the old 25" series see Trinity Map Library's description. The newer 1:2500 series covers suburban and peri-urban areas and is revised approximately every 3 years.
1:5000 (approx. 12" to 1 mile): mapping at this scale covers rural areas and is updated approximately every 5 years.
1:10,560/(6" to 1 mile) : maps at this scale are available for the whole of Ireland but have not been updated since the 1930s. For more information about this series see Trinity Map Library's guide on 6" maps.
1:50,000 Discovery Series. Richview Library has complete sets of these series.
List of Map Scales
Gives conversion of scales from ratio to standard measurements.
See both documents below for scales and their equivalents.
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List of Map ScalesGives scales in ratio, inches and feet and metres and kilometres
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Common Map Scales & Their EquivalentsThis is an alternative document which gives map scales and their equivalents in inches, centimetres, miles and kilometrres.
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Scale CalculatorScale Calculator is a free map tool from the Bureau of Economic Geology which allows you convert and calculate map scales.
OSi Characteristic Sheet
The OSI characteristic sheet provides a guide to symbols used on the 25inch and 6inch maps.
Indexes
Visual index maps: these exist for most of the series of maps in stock in Richview Library and provide a visual way of relating the area you require to an Ordnance Survey Ireland (OSI) map number.
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Indexes to the 1/2500 and 6-inch scale maps and small specimens of different maps published byPublication Date: [1908]Visible indexes for all published 25 inch and 6 inch maps for the 32 counties on the island of Ireland.
Tools for Finding and Converting Coordinates
General information on geographical co-ordinates and map projections are provided here on the ICA Commission on Map Projections website
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CoordtransCoordTrans converts geographic coordinates between different coordinate systems.
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Find latitude and longitude using Google MapsView the single image to see how to get the longitude and latitude coordinates for your site or address
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The World Converter ToolView the single image for an example of how to use TWCC. "The World Coordinate Converter", is an Open Source tool to convert geodetic coordinates in a wide range of reference systems.
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Ordnance Survey Ireland Coordinate ConverterIn this example the numbers 681693 and 637876 were typed into the ITM Easting and Northing boxes. Click on Convert. The coordinates will pop up in the other standard co-ordinate systems, i.e. Lat / Long, UTM and Irish Grid.
Link to OSi co-ordinate converter: https://gnss.osi.ie/new-converter/
The OSI website also provides a free downloadable co-ordinate converter at: https://www.osi.ie/services/geodetic-services/download-co-ordinate-converter/
OSi Presentation on Scales
Click on the Powerpoint below for an OSi presentation on large and small scale mapping.
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Scales and MapsThis is a Powerpoint presentation from OSi which explains large scale and small scale mapping
Enlarging and Reducing Sheet Maps
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original scale: |
% to select on copier: |
map scale now equals: |
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|
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1:1000 |
200% |
1:500 |
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1:500 |
200% |
1:250 |
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1:500 |
250% |
1:200 |
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1:250 |
125% |
1:200 |
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1:1000 |
50% |
1:2000 |
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1:2000 |
80% |
1:2500 |
US Geological Survey Scales Fact Sheet
This Fact Sheet from the US Geological Survey describes and explains how scales work in maps.
Creative Commons license
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