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Born-digital documents. Screenshots from Google Earth and oXygen.
Most
mol:
prefix and accessed through the web application
with their id + .xml
.
The molagas prefix points to the shape representation of a location on
Links to page-images in the Chadwyck-Healey
Links to page-images in the
The mdt (
The mdtlist (
_subcategories, meaning all subcategories of the category.
The molgls (
This molvariant prefix is used on
This molajax prefix is used on
The molstow prefix is used on
Our editorial and encoding practices are documented in detail in the Praxis section of our website.
s/heand
his/herto
theyand
theirrespectively.
Any place on the surface of the earth can be located in terms of three coordinates: latitude, longitude, and elevation (height above sea level). In most of our work, we are concerned with only the first two, latitude and longitude, because we don’t (currently) envisage any rendering or data processing that would make use of elevation.
Traditionally, latitude and longitude were expressed in degrees, like this:
51°30'49.25"N
0° 5'58.42"W
In modern GIS systems, latitude and longitude are expressed in decimal numbers, which look like this:
51.513557
-0.098369
Coordinates like this are usually comma-separated, like this:
51.513557,-0.098369
51.513557,-0.098369,0
At the moment, historical geo-coordinates are not nearly as readily available as modern-day geo-coordinates. Generally speaking, those who wish to work with historical geographic data are expected to infer geo-coordinates from their own research. We can infer the geo-coordinates of early modern locations from the geo-coordinates of modern administrative boundaries, sites, and structures.
LAARC is a database of site records from archaeological digs in London. Each site record has been assigned geo-coordinates that correspond with the point where historical evidence of the location was discovered by archaeologists. Site records are searchable via the website’s home page. Note that even though it is possible to search by street name, LAARC provides point-based geo-coordinates for archaeological finds under modern streets, not line-based geo-coordinates for the early modern streets themselves. LAARC usefully lists all the scholarly articles and monographs about a particular dig, from which we can derive further information.
ShaLT maps all the early modern London theatres and provides resources, maps, and suggested walking tours. Each location (exclusively playhouses and related locations) has been assigned geo-coordinates that define where the location existed in Shakespeare’s London (defined as locations
page. We have now added all of the ShaLT coordinates to our playhouse location files.
GeoNames is a global database of geo-coordinates that contains over 100 modern-day locations in the City of London. Locations are searchable by toponym at the website’s home page and visually via the website’s map widget. Note that GeoNames is a modern-day gazetteer. Geo-coordinates for a modern-day location may not perfectly correspond with the location’s early modern predecessor.
Locating London’s Past is a GIS interface that links various seventeenth- and eighteenth-century datasets with a georectified version of John Rocque’s
In many cases, you will be unable to find geo-coordinates for a location using the resources listed in the previous section. When this happens, you must use your own research on the location to infer its location on a modern-day, Google map of London. The following sections describe how to extract geo-coordinates manually for user-selected points, lines, and polygons using Vertexer
—a Google Maps markup tool developed by
Vertexer is an open-source web application that allows users to draw points, lines, and polygons onto a Google Maps widget with map, satellite, and terrain views. It may be accessed via the following url: http://hcmc.uvic.ca/people/greg/maps/vertexer/?la=51.51&lo=-0.1&z=15&t=roadmap. The preceding url uses bookmarks to preset the application to zoom in and centre on the City of London. You may navigate the map by dragging it with the white hand cursor () or using the search field in the top-left corner of the screen. You may switch modes between a traditional map view and satelite view of an area using the drop down menu in the top-left corner.
A point consists of two geo-coordinates, a latitudinal and a longitudinal coordinate, separated by a comma. We use points to infer the approximate location of buildings and other topographical features that no longer exist in present-day London. To extract geo-coordinates for a point in Vertexer, select the point marker ( from the toolbar in the top-right corner). Click on the map to produce geo-coordinates for a point (i.e., the point where you click). Geo-coordinates will appear in a pop-up. These coordinates may be copied to your clipboard and pasted into the TEI document for the coordinates’ corresponding location.
For example, suppose that I want to extract geo-coordinates for St. Olave, Silver Street (STOL4.xml). There is a present-day monument at the southeast corner of London Wall and Noble Street that marks where the church once stood. By referencing this monument, I can easily place a point marker on the former location of St. Olave, Silver Street in Vertexer:
Notice that the geo-coordinates for the point marker (and, by association, St. Olave, Silver Street) appear in the bottom half of the screen. They are as follows: 51.517297,-0.095127
.
A line consists of at least two sets of latitudinal and longitudinal coordinates. Regardless of how many sets of geo-coordinates make up a line, the first and last set of coordinates will always be
For example, suppose that I want to extract geo-coordinates for Carter Lane (CART1.xml). Carter Lane still exists in present-day London, so I can easily trace the present-day Carter Lane in Vertexer:
Notice that the geo-coordinates for the line (and, by association, Carter Lane) appear in the bottom half of the screen. They are as follows:51.513361,-0.102725 51.513313,-0.102248 51.513291,-0.101983 51.513289,-0.101963 51.513283,-0.101892 51.513272,-0.101785 51.513258,-0.101681 51.51325,-0.101636 51.513148,-0.101284 51.513137,-0.101239 51.513126,-0.101197 51.513099,-0.101073 51.513041,-0.100525 51.51296,-0.100191 51.512924,-0.09914 51.512888,-0.098421 51.512883,-0.098297 51.512794,-0.09733 51.512796,-0.097315 51.512808,-0.097288 51.512822,-0.097272 51.51283,-0.097262 51.512852,-0.097245 51.51295,-0.097186 51.513033,-0.097205
Notice also that the various points along the line are marked with a white circle. After you have finished drawing a line, you may edit its shape and geo-coordinates by clicking on and moving these point markers. You may also right-click on any point marker to delete it.
A polygon consists of at least three sets of latitudinal and longitudinal coordinates. Regardless of how many sets of geo-coordinates make up a polygon, the first and last set of coordinates will always be
For example, suppose that I want to extract geo-coordinates for St. Paul’s Cathedral (STPA2.xml). St. Paul’s still exists in present-day London, so I can easily trace the present-day St. Paul’s in Vertexer:
Notice that the geo-coordinates for the polygon (and, by association, St. Paul’s) appear in the bottom half of the screen. They are as follows:51.513412,-0.099565 51.513425,-0.099074 51.513375,-0.098548 51.513327,-0.098267 51.513405,-0.097975 51.513615,-0.097346 51.513829,-0.097254 51.514032,-0.097449 51.514108,-0.098133 51.514195,-0.098399 51.514088,-0.098687 51.513987,-0.099116 51.51393,-0.099637 51.513412,-0.099565
Notice also that the various points in the polygon are marked with a white circle. After you have finished drawing a polygon, you may edit its shape and geo-coordinates by clicking on and moving these point markers. You may also right-click on any point marker to delete it.
Do toggle between the map view and the satellite view when drawing a polygon. Features of a building or site can be clearer in one view than they are in the other. For example, the map view of St. Paul’s Cathedral does not show clearly that the north and south semi-circular features are gardens. The satellite view helps one determine the shape of the structure, even though it is easier to trace the structure on the map view.
It is possible to edit a complex line or polygon even once it has been encoded inside an existing locations document. To edit a pre-existing line or polygon, copy and paste its geo coordinates (tagged using the New Shape
field in the bottom-centre of the interface. Next, click on the Add shape to map
button. The line or polygon will then appear on the map, where you may edit it by moving and/or deleting its white point markers. You can then copy and paste the shape’s edited geo coordinates back into the existing locations document.
For instructions on how to perform the same tasks using Google Earth, see
Once you have retrieved geo-coordinates for a location, the next step is to encode them in the location’s TEI file. Each TEI file for a location will have a
The comment indicates where the coordinates should go. Paste the coordinates inside the
A geographical line should be encoded thus:
A geographical polygon should be encoded thus:
It is important that we remain transparent about the source of the geographic data that we use and who has acquired it on behalf of
To encode source information for a set of geo-coordinates, add a
Separate the first and second value components with a single space character ( ). If you used Vertexer to extract geo-coordinates, cite Vertexer (VERT3) as the source. Do not include an http:// address in the
The following example presents the geo-coordinates for Silver Street as sourced from
To encode responsibility information for a set of geo-coordinates, add a
Note that the
We also encode responsibility information for geo-coordinates in responsibility statements in the Geographic Information Specialist
for the document. Use the molRelator code gis
in the
See
Whenever possible, it is best practice to define a date range for geo-coordinates (i.e., identify from when to when the location corresponded with the given geo-coordinates). Refer to the source of the geo-coordinates as well secondary material about the geocoded location to obtain relevant date information. To define the date range for a set of geo-coordinates, add
Occasionally, you will encounter locations that existed in both early modern London and present-day London. With a few exceptions, such locations will have moved — slightly or significantly — from their early modern site. For example, St. Paul’s Cathedral and Goldsmiths’ Hall have been rebuilt on the same sites but not with the same building footprint. Most sites within the walls were rebuilt after the Great Fire of 1666. The surviving streets might be truncated, blocked at one or both ends, or bisected. The few surviving alleys and lanes have been truncated. We therefore supply today’s date (i.e., the date you extracted the geo-coordinates) in lieu of a date range for the present-day geo-coordinates. To define a present-day date for a set of geo-coordinates, add
For further information, see
Locations in the
Multiple geo-coordinates can be encoded in a location document using one of two methods:
Use
Use
Note that you may encounter situations or complexities when working with geographic information that are not covered in this tutorial. In such instances, use your discretion to decide which method of encoding is best suited to the geographic information you are working with and flag the issue for discussion with Janelle and/or at a team meeting. Complexities are an opportunity to refine our practices. As a general rule, use
In certain instances, you may wish to add geo-coordinates to a non-location document. For example, the encyclopedia article on the Revels Office (REVE2.xml
) contains location information and geo-coordinates for the various sites of the Revels Office
Seeing as non-location documents do not by default contain a
Follow the instructions in the previous section to add content to the above template and, in doing so, encode geo-coordinates in a non-location document.