Brooklyn College Library LibGuides Home: Mapping and GIS Lessons for Poets, Historians, and Scientists: Activity: Playing with Historic Maps

Using Historic Maps: Sources

Objectives:

Explore the features of two repositories of Historic Maps: HyperCities, and David Rumsey Map Collection.
Practice "Georeferencing" in Hypercities and David Rumsey Collection.
Download a map as an image and as a kml layer. Later, this can be opened directly in GE.

Discussion Questions

Consider the contrast between your historic map and the modern platform.
What are the benefits or disadvantages of seeing antique and modern maps superimposed ? What does changing the degrees of transparency of the old map show you?
What are some of the difficulties of working with "image overlay" ?
Did your image line up easily on the modern map, or did it have to be warped to fit?
What do the two maps tell us about subjectivity or objectivity in the visualizing of real-world information?
Contrast Hypercities and Rumsey for their research on maps. What kind of information can you learn from the "map details" of each? Where does each map come from? In what format is it available?

Learning Outcomes

Gain facility with overlay of historic maps on modern maps. Investigate process of georeferencing, and learn importance of correct procedures.
Develop sense of appropriate research and documentation of historic maps in ancient and modern digital formats.
Practice "Georeferencing" in Hypercities and David Rumsey Collection.
Download a historic map as an image, and as a kml layer. Later, we can add these directly to Google Earth.
Further explore and analyze other repositories of Historic Maps: including NYPL Map Warper, ArcGIS, and Google Map Geodatabase.

Hypercities Map Library

View Image Overlays of Antique maps in Hypercities:

In the left hand search box, search on a city name of your choice. If nothing comes up, choose a different city until you get a hit. Select the historic map, and open in the Hypercities viewer. Play with the transparency slider on the upper right. Examine the "Map details."

David Rumsey Map Collection
"The David Rumsey Map Collection began digitization in 1996 and there are now over 90,000 rare antique and historic maps online. The collection includes atlases, wall maps, globes, school geographies, pocket maps, books of exploration, maritime charts, and a variety of cartographic materials including pocket, wall, children's, and manuscript maps. Items range in date from about 1550 to the present.
The site is free and open to the public. Here viewers have access not only to high resolution images of maps that are extensively cataloged, but also to a variety of tools that allow to users to compare, analyze, and view items in new and experimental ways." (David Rumsey About Page)
Rumsey Collection for Google Earth
Downloads a kmz file containing all Rumsey maps viewable in Google Earth.
Random Map Georeferencer: Rumsey Collection
Every time you click on this link, a new map will pop up at random in the Rumsey Georeferencer. For instructions on practicing with the Georeferencer, click "more" link below.

more...less...
(Source: David Rumsey Georeferencer Home)

Practice with the Rumsey Collection Georeferencer:

Experiment with the "Georeferencer" tool in the Rumsey Map Collection.

Georeferencing historical maps enables new understandings of the maps by comparing them to modern maps through visualization and analysis. It also creates the ability to search old maps for locations and to compare old maps to each other. Use the Georeferencer tool to place location points on the old and new reference maps. This can take some time but the results are very satisfying both to the user and as a contribution to our online library - other users will be able to make use of all georeferenced maps. Once maps have been georeferenced, they can be found through the LUNA viewer or at the Georeferenced Maps page. The various pages for the process have ? buttons to provide detailed help as needed.

The steps of georeferencing are as follows:

1. Choose a map to georeference, either with the Random Map button or the Search LUNA... button.

2. The map will open on the right side window with a modern map in the left side window. For more information about the map, click on the This Maptab.

3. You have several choices of modern maps to use, click on the upper left Globe symbol menu to choose the best one for the area in question.

4. If the historic map location is not clear, find the name of a town or street and search on that term in the modern map search window.

5. Use the zoom in + or out - button to navigate the maps, or the scroll wheel on your mouse.

6. Find common locations on the old and modern maps and place sets of points on each. Three points are the minimum required, but more than three points will increase accuracy. Use the Coordinates tab to detect errors.

7. Spread the points as evenly as you can across the maps for better results. Try to extend points to the map margins. If you make a mistake with any point, mouse over a point and hit delete, then re-position the point and click on the map until the points number shows.

8. When you are finished placing points, use the Clip tool to crop the map just inside the map border. This will make the map blend more easily at the edges with the modern map and also define the area of the map's coverage in our database. Then click on the orange Save button and the map can be viewed in the This Map window and the Georeferencer Compare window. If you have not logged in you will be asked to - setting up an account is free.

9. You can view the historic map in 2D or in 3D or using the Side-by-side viewer in the Georeferencer Compare window. Maps that show mountains and other elevated areas will use the built in DEMs (Digital Elevation Models) in the 3D viewer to show those areas in three dimensions.

10. In the Overlay & Compare page (Georeferencer Compare) you can view one map or search for maps from various sources, and then compare them using several different views - Overlay, Grid, Swipe, and Spy glass.

11. If the map needs correction or refinement of points, sign in and click on the Georeference tab in the This Map window and you can add or correct points. To get to the Georeference tab if you are in the Georeferencer Compare view, just click on the name of the map in the upper right box. Use the Coordinates tab to identify inaccurate points. Remember that very old maps may have inaccuracies in the original cartography and understanding the degree of these inaccuracies is one of the things that Georeferencer makes possible.

12. Polynomial and TPS views of the map use more complicated calculations to render the map and may result in more accurate renderings, but they will require more points to be made and they may distort the shape of the map. The default view is Affine, which will stretch the map but not alter its shape.

13. The Cutline (the box made with the Clip tool in the Georeference tab) may be turned on and off by checking and unchecking the box next to theCutline label in the Cutline tab view.

14. From the This Map pages, use the GeoEditor to locate and measure areas, distances, locations, and more. Use the Transcribe feature to annotate the maps.

15. Advanced users will be able to export the georeferenced map using the Use in GIS apps - Get Link in the lower left of the This Map view. This will enable viewing the maps in various GIS web based and desktop programs.

16. If you find bugs or problems, use the Hamburger drop down menu in the upper left corner of all screens to send us a message about the problem with the Send Feedback tab.

17. Klokan Technologies developed Georeferencer with the Moravian Library. You can combine and compare maps found at the Georeferencer pages at the National Library of Scotland and the British Library, along with maps from our collection in Georeferencer, as well as all the maps in Old Maps Online.