There is no index to the images of individual early maps on the web. It is likely that there are now (December 2007) several hundred thousand early map images. The accompanying listing deals with sites, not single images. So, how can you find what is out there? Probably, you want maps of a particular part of the world. For that reason, the listing is arranged geographically. As you would expect, a collection based in an area is likely to be strong on maps of that area. However, confusingly, a number of sites range more widely. Always check out those in the 'General and Miscellaneous' section, and try those in the broader region that contains the area you are really interested in: United States or North America, for example, when you want a particular state. Equally, early maps tended to cover a wide area, so those who mount 17th century maps of their country or state will often put up maps of a much wider region.
For a joint search on the David Rumsey and a handful of other collections, see Visual Collections: images of art, history and culture.
Some sites go beyond this 'Map History' site in the detail they provide for a given area, even sometimes including links to separate images. The best way to retrieve those would be to search the individual pages of the Images section for gateway and links.
Alternatives to geography might be:
The following categories have been systematically excluded:-
Most images appear on your screen, along with the text, without your having to do anything special. What you may see at first is a small 'thumbnail'. In these cases, it is always a good idea to try clicking on the image (or, occasionally, on a text link or magnifying glass nearby). If this is going to be possible, place your mouse cursor over the image - or over where it will be emerging - and it will appear as a pointing hand rather than an arrow. That is a sure indication that this is a link to a larger version of the image. You do not have to wait for the first version to appear before starting to load the larger version. Sometimes you can enlarge several times. Alternatively, if you right click with your mouse you may be offered a 'zoom in' option.
The larger images may be 'scrollable' and, occasionally, 'zoomable'. Many original maps are larger than a computer screen. The most helpful sites - or those that can find the resources of time and money for this expensive operation - enlarge the map image well beyond its original size. You can then scroll (or pan), up/down or sideways, until the part you want is in view.
That is a way of treating an entire map as one large image. Another method is to invite the user to click on the section of interest and then zoom into that detail at an enlarged scale. Among the more popular programs to achieve this are JPEG2000, MrSID, Insight and Zoomify. These allow you, simultaneously, to enlarge an image and zoom into a detail, see for example the Library of Congress 'American Memory' site and David Rumsey's Collection online. For details about those two sites see under Large general sites. For information about the programs mentioned see Software requirements.
The following sites have been ransacked (with grateful acknowledgement) for their relevant links. The PCL site includes some single image sites, as well as many 'historical' maps (i.e. modern reconstructions). Neither of those types has been included in this listing:-
The comments about image 'resolution', given in the brief description to each entry in the listing, refer to the appearance of the map. They are not intended to be understood as technical observations, for example about 'dots [or pixels] per inch' (dpi), or the way the image was scanned or compressed.
'High resolution' is used to indicate map images whose place-names - even the small ones - are easily readable. This seems to me the most important consideration. It may be possible to read some of the place-names on 'medium' resolution images. Unfortunately, many of the images mounted on the web are of low resolution so that, even when the map fills the screen (and sometimes when a zoom option is available), details are blurred and the place-names illegible. This particularly applies to pdf images. Low resolution images give a general idea of the map's appearance but are of no use for serious study, whether you are a scholar or someone researching your family history. You need to be aware that image quality will also depend on the speed and age of your computer. It may be that the images appear to you better or worse than they do to me. However, 'high res.' should always appear clearer than 'medium res.'
It is easier to provide a high resolution image of a 'miniature' map (where several originals could fit onto a single computer screen) than of a standard map that will be larger (sometimes very much larger) than the screen. For that reason you will find a lot of miniature maps on dealer sites!
There is often a balance between image quality, the time taken to download the map, and the cost of storage space. You should not expect a clear image, occupying, perhaps, twice the size of your screen, to be delivered instantaneously. Even if most people will not wait more than 30 seconds for a page to load, you may have to be the exception. However, some relatively poor quality images are slow to load, although it must be pointed out that loading speed can vary for a number of reasons. It is also possible that some of those sites I have described as 'slow-loading' will have improved their delivery by the time you go to the site. At the other extreme, the best sites offer fast-loading, high quality images (see under Software requirements).
To search in the listing for high quality, press Ctrl+F and enter: high res. If you want speed, enter: fast-loading. To find those that have both virtues, enter: fast-loading, high res. Alternatively, search for JPEG2000, MrSID, Insight, Zoomify etc..
It is generally accepted that 300 dpi (dots per inch) is the minimum resolution for acceptable image capture - from the original - of the full version of a map. Those on the Project Pont site, for example, are delivered at 400-700 dpi and the National Oceanic and Atmospheric Administration's Historical Map and Chart Collection at 800 dpi. Scanning from a slide or microfilm, like those in the Hargrett Library's Rare Map Collection at the University of Georgia, which were 'scanned from microfilm negatives at 2400 dpi', does not necessarily lead to clear images, unless the originals were unusually small.
In some cases, a lower resolution version might have been intentionally mounted on the web, for example for copyright reasons. The development, and widespread use, of effective digital 'watermarking' may solve this security problem.
It needs to be remembered that when maps are scanned at 300 dpi, this is several times the resolution of a normal PC monitor (about 72 dpi). Viewing an image at 100% or 1:1 will usually mean that what you are seeing is about four times larger than the original! This is why, to achieve full legibility, most maps need to be enlaged well past their original size.
File sizes may vary enormously. They can be expressed in pixel (or 'Window') size (e.g. 640 x 480) or in bytes. The file size might range from 50 Kb for a small, low resolution image, to an average 150 Mb (over 150,000 Kb) for those on the David Rumsey site, rising to two gigabytes (over 2 million Kb) for the largest files on that site. The use of MrSID software (as part of 'Insight') ensures that these large files can be delivered speedily, because they may have been compressed down to as little as 3% for delivery. JPEG2000 is an open source compression technology. On JPEG2000 see notes by the Library of Congress.
Images will usually have the extension .gif or .jpg.
Some sites require you to download viewing software, if you do not already have it stored on your PC. This is usually available free of charge, though you may need to buy software if you are going to create images. You can find general information about this, and particularly on MrSID and FlashPix, in David Yehling Allen's 1998 article, 'Creating and Distributing High Resolution Cartographic Images'. Some of these programs work on the principle of partial delivery, saving bandwith and, simultaneously, protecting the image owner from having an entire image removed for reuse. See also Creating map images . For more specific information about the software you may encounter, see the following:-
On this, see the explanatory page, 'Citing Electronic Sources' (part of the Library of Congress 'American Memory' site). This has examples of two different citation formats, and a list of links to other relevant sites.
The United States Copyright Office site has information on the US position, and links to other sites
For an analysis of (US) copyright issues by Georgia Harper of the University of Texas, see 'Fair use of copyright materials'. From the same university there is also a Copyright Tutorial
’The Ultimate Student Guide to Images’ (about the situation in the USA - stinkyink.com)
'Orphan Works: Statement of Best Practices' ('Standards, Guidelines, and Best Practices' from the Society of American Archivists, June 2009)
'Overview of Legal Issues for Digitization' by Melissa Smith Levine (Legal Advisor, National Digital Library Project, Library of Congress), Chapter V in Handbook for Digital Projects: A Management Tool for Preservation and Access
Association of Research Libraries (ARL). 'Federal Relations and Information Policy' (tracking the 'activities of legislative, regulatory, and government agencies and related organizations in North America and abroad that impact research libraries'
’About Intellectual Property’ (World Intellectual Property Organisation)
EBLIDA (European Bureau of Library, Information and Documentation Associations) is an independent umbrella association of European institutions, focussing, inter alia, on copyright
The situation in the UK is explained in the government site, Intellectual Property (UK Intellectual Property Office - an operating name of the Patent Office)
'10 Big Myths about copyright explained' (Brad Templeton)
The experience of examining thousands of map image sites [those in the listing and a considerable number that were rejected] has made me aware of their variety, and the great range in terms of quality and usefulness. Since you are unlikely to repeat this exercise, I offer some thoughts and suggestions prompted by it.
The most effective sites are those with a clear purpose: perhaps a selection of maps of a particular region (which is the way that this listing has been organised) or those concentrating on a single subject (see Themes). Often, however, the motive seems to be 'window-dressing' - an attempt to show a few, random samples. Many of the sites listed under Medium and small general sites are like that - and hence unclassifiable. Please seriously consider a focussed approach.
In determining the purpose of web-mounted map images, deciding on image quality is as important as the selection of maps that are going to be scanned. Why are you offering these maps to the world? What do you think the viewers should/could/will do with them? If they are meant to permit people, anywhere, the same type of access as you (assuming you are an institution) offer to those who handle your originals, then you need to take a route that ensures sufficiently high quality to allow every single place-name to be read. Anything less and these are not true surrogates. It would be helpful if, in the context of digitisation, each map was treated as if it was a text, rather than just an image, and as a text that employs unusually small type faces. The capital letters of Times New Roman, for example, stand 2.5 mm high in Word size 11 (a standard reading size), yet the names on early maps can go down to 1.5 mm or even to 1.0 mm. This is far smaller than would ever be used in a connected text. Yet it is precisely those names - the lowest in the hierarchy - that are likely to be searched for, not the names of large towns or regions. For this reason some sites link the images to lists of place-names [search 'Images of early maps' for 'gazetteer' or 'place-names'].
Alternatively, if you use one of the high quality programs, you may be opening up new, and exciting, possibilities [see 'Innovative sites' for examples] allowing maps to be viewed clearly at a larger size than the original, and compared side-by- side on a single screen with another example from a different collection. Why not search the listing [Ctrl+F] for fast-loading, high res. sites and see how they have done it?
Even when somebody has found your site, their problems may not be over. Because so many web designers seem to forget about the site's users, navigating within a site can be like finding your way in a maze. There is often no apparent structure to the various pages. And that, of course, assumes the viewer has managed to see the pages at all. Some designers are more interested in clever graphics than in speed of loading. People who seek maps have little or no interest in where they are stored (physically or in web space). When the images are scattered, could there not be a single index [i.e. a list of hyperlinks] to all the web-based maps in that institution? If you are a map librarian or curator please try and persuade your 'Webmaster' of this. It is unlikely that anybody else will!
Please consider providing one or more indexes, if you are involved in a larger image site (say, with over 100 images). The very Large general sites already do this. The problem is that individual maps are hard to find on the web (see Search engines).
The question of cataloguing standards appropriate for digital map images, and the resources that might or might not be available for that, are too big to be dealt with here. But for map scans to serve their full useful purpose it is clearly essential that they are accurately described. Since maps tend to have been copied from earlier models, a common mistake is to assume that the date of publication is the same as the date of the information. For a good, individual example of this see a message from Peter van der Krogt to the MapHist list (13 January 2007).
In many cases, loading map images onto the web is seen as an end in itself. Some sites, however, provide 'added value', in various ways that might serve as models to others. For more information on these sites see the appropriate geographical page in the Web Images section
Updating that note (in February 2013) it is worth recording how much has been done in the intervening years to enlarge and enhance the NLS site, now including almost 50,000 high resolution images, among them comprehensive Ordnance Survey coverage for Scotland. The three salient features persist: clear organisation; informed commentary; and navigation that puts the user first, with good search options and a new 'Explore Georeferenced Maps' option. I hope many of its features will be imitated by others.
Also from Scotland, 'A history of Orkney maps' by John K. Chesters constitutes a research site with an original methodology, using overlays and error diagrams to arrive at a map lineage. From this it concludes that "the development of the cartography of Orkney has not been a smooth progression through time but has depended on a relatively few surveys and their associated advances in surveying techniques". The 'Methods' section (follow the 'Next' button) is the equivalent of an online essay.
Melanie Lovell-Smith's 'Early Mapping', in Te Ara - the Encyclopedia of New Zealand should be followed by others as an example of how to build a clearly laid out, helpfully interconnected and thoroughly researched site covering a wide range of related topics. For further comments see Web Articles: 11. Australia and Oceania.
The site investigating the 12-sheet Nolli map of Rome (1748) provides a Flash-based, high resolution, interactive version, which analyses and indexes 1,320 features and allows you to select and zoom into them, see the Preface.
There are three sites by Jean and Martin Norgate full of imaginative ideas. The first is 'Old Hampshire mapped', in which each of 24 maps has been made the subject of a detailed, comparative investigation into its history and content, and the results presented in the form of text, close-up images, etc. Because details of each map have been captured using a uniform grid system, it is easy to pull up the same area on different maps (at the same apparent scale) or to jump to the appropriate map area from a gazetteer name link. Under 'Topics' you will find extensive comparative notes on a wide range of cartographic features. For fuller explanation see their Project Note, and J. & M. Norgate, 'Old Hampshire Mapped', Cartographic Journal 41:1 (2004), pp.47-53. Also look at the Sussex site, created by Dominic Fontana on the same (if simplified) model. The second is the Norgate's interactive facsimile of Edmund Dummer and Thomas Wiltshaw's South Coast Harbours 1698. This is similarly rich in its functionality and treats, for example, some key letters on the charts as hotspots with ALT text explanation. Finally, see Martin Norgate's Checklist of Hampshire Maps - again another complex site, demonstrating further imaginative functionality. For further information on all three Norgate sites see the descriptions on the Web Images: British Isles page, under 'England - Hampshire'.
What can digization lose?
‘What Disappears When Ancient Documents Get Digitized?’ (a balanced piece by Jacob Brogan about the Osher Map Library’s digitisation programme describing what is gained and lost, 22 July 2016)
The archive of the MapHist list will show that, over the past few years, there has been much discussion about the need to index map images on the web. The ideal would, of course, be to catalogue each image fully. But, to find what a person wants, an index is usually sufficient. This listing - the first systematic attempt to record all significant early map image sites - could be used as the first stage in that cataloguing or indexing process, by anyone courageous enough to attempt the task. [They would be assured of 'Hero of the Web' status is they succeeded!]. It might be thought that the only images worth indexing would be the high resolution ones. [To find these on the listing, search [Ctrl+F] for: high res.]. Some of the largest such sites - like the Library of Congress 'American Memory', NOAA's 'Historical Map and Chart Collection' and David Rumsey's private collection - have their own indexes. The problem is that you cannot search, simultaneously, across all of them. Nor can you search, at all - by area, cartographer, date, etc. - for single images mounted on the other high resolution sites.
When you mount early map images for the first time, or include a group of new ones, please notify me or send a message to the MapHist list. You do not need to be a subscriber to do this. For details, see the MapHist page on this site. Please also make a point of notifying me if the URL changes, especially if no forwarding message is left!
Please send amendments to the compiler Tony Campbell:
Will these images be available in ten years' time? Who is thinking and planning about long-term storage?
Thanks are due to various experts for their tutorials. Only the compiler can be blamed for what he has failed to understand -