A Brief Guide to Map Elements

The Oxford English Dictionary Online defines a map in this way:

A drawing or other representation of the earth's surface or a part of it made on a flat surface, showing the distribution of physical or geographical features (and often also including socio-economic, political, agricultural, meteorological, etc., information), with each point in the representation corresponding to an actual geographical position according to a fixed scale or projection; a similar representation of the positions of stars in the sky, the surface of a planet, or the like. Also: a plan of the form or layout of something, as a route, a building, etc.

This brief guide will review the most common map elements, how they are useful in 'reading' a map, and provides examples from the maps in the collection.

Direction

Most maps include a "North arrow" to reference direction on the map. The North arrow on a map is usually located in or near the map legend. If a North arrow does not appear on the map, North is assumed to be the top of the map.

North arrow from Plan shewing the situation of a Mill-pond Right on Lots 6 and 7, purchased from Samuel Sweet, by Richard Smallman (Undated)

North arrow from Plan of Town Lots at Cascumpec Point. Township No. 5. (1877)

There are other types of "North" that can be shown on maps. Most topographic maps will show the difference between true, magnetic and grid north. Magnetic North is the north magnetic pole. It is currently located in Nunavut at 78oN 105oW. The north arrow of a magnetic compass points toward the North magnetic pole. (Note: the difference between true north and magnetic north is call ed magnetic declination.)

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Magnetic and True North from Plan of Township No. 11 (1910)

Magnetic and True North from Map of the Province of Prince Edward Island, in the Gulf of St. Lawrence (1880)

 

Magnetic and True North from Plan of Township No. 9 (1909)

Grid north is an artificial north that is used on maps which have a rectangular grid. The vertical lines do not converge as one proceeds northward. These maps are most commonly used for navigation.

 

Grid North from Prince Edward Island (1798)

 

Scale

Scale is the ratio between distance on the map and how it relates to distance on the ground.

An example of a scale that you will commonly see referenced on maps in the collection is a "representative fraction", for example in Meacham's Atlas you often see a scale of chains to inches.

scale 50 chains to one inch
 Scale Example from Plan of Lot Fifteen, Prince Co. (1880)

 

In the above example, 1 inch on the map represents 50 chains on the ground.

During the time when much of the Island was surveyed, the chain was a common unit of measure. A chain is 66 feet long or 100 links and an acre has an area of 10 square chains.

Measuring Chains. HF..... Photo Credit: Kris Bulman
Chains. PEI Museum and Heritage Foundation.
Photo Credit: Kris Bulman

On many other maps in the collection you'll see a Graphic Bar (or bar scale). Below is an example from an 1841 map.

Graphic Bar Scale
Plan of the Western Portion of Township No. 65

by the surveyor C. Wright.

The graphic scale printed on a map allows a person to measure distances on the map in terms of ground distances.

Two other examples of scales based on the chain systerm include:

The scale taken from Plan of 117 ½ Acres of Land in the possession of James C. Wright surveyed by John Clay (1879).

 

The scale taken from Plan of Town Lots at Cascumpec Point. Township No. 5 (1877).

Scale also utilized other measurements to convey distance including leagues:

Legend taken from Untitled (1760)

 

 

Map Legends

The legend is the key to understanding the map and, together with the title, is the first place you should look when reading a map. The map legend explains the meaning of symbols used on the map. Here are some examples from the collection.

 

Legend from Goad fire insurance map:

Legend taken from Cardigan P.E.I., Kings Co.: Population 300. No Protection. (October, 1910)

Legend from C.R. Allen Map:

Legend taken from Map of the Province of Prince Edward Island, in the Gulf of St. Lawrence (1880)

 

Inset Maps

Some maps feature inset maps— smaller maps on the same sheet of paper.

Inset maps provide additional information not shown on the larger map. 

Inset taken from Plan of Lot Thirteen, Prince Co., P.E.I. (Undated)

Inset maps are drawn at a larger, more readable scale.  

Inset taken from Plan of Lot 27, Prince Co., P.E.I. (1880)  

Inset maps usually features areas of interest related to the larger map.

Inset taken from Plan of Lot Fifteen, Prince Co., P.E.I. (1880)

Credits

This guide borrows from the following sources:

Reading Maps: A Brief Guide to Reading Maps produced by Statistics Canada.

Maps and Cartography: Maps Tutorial: The Elements of a Map by Ball State University Libraries