source: trunk/london.npemap.org.uk/FAQ.html

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<a name="whatMaps"></a>
<h3>What maps are you using?</h3>
<p>We currently have permission to use two different maps, but only one
 of them is currently scanned in and online.</p>
<p>The first map is "Geographers' Authentic Map of London" from 1956. This
 has half mile grid squares, is in black and red, and covers an area of
 13 miles by 8 miles. This one is currently online.</p>
<p>The second map is "Geographers' Six Inch Map of Central London" from 1951.
 This has quarter mile grid squares, is in colour, and covers just central
 London. This one is currently pending scanning.</p>

<a name="copyright"></a>
<h3>Are these maps out of copyright, like the other maps on
 <a href="http://npemap.org.uk/">npemap.org.uk</a>?</h3>
<p><strong>These maps are still in copyright.</strong></p>
<p>These maps were produced by the Geographers' map company in the 1950s,
 based on Ordnance Survey data, and their own surveying and cartography.
 The crown copyright on the OS data in these maps has now expired. However,
 the Geographers' map company (now Geographers' A-Z Map Company) copyright
 remains, and will do so until 70 years after the death of the last 
 cartographer who worked on the map.</p>
<p>We have received permission from the Geographers' A-Z Map Company to
 post these maps online. However, they must not be copied or reproduced
 without prior permission from the Geographers' A-Z Map Company.</p>

<a name="licence"></a>
<h3>What licence are these maps under?</h3>
<p>We have received a non-transferable non commercial use licence to display
 these maps on the site, from the Geographers' A-Z Map Company. You will
 need to get a licence from them if you wish to make use of these maps
 yourself.</p>
<p>The Geographers' A-Z map company have indicated that they do not consider
 extracting small amounts of geographic information from these maps to be a 
 breach of their copyright. Examples might be the old name of a few roads
 around your house, or the location of a closed tube station. If you wish
 to extract large amounts of information (such as many road names, or tracing
 noticable parts of the map), you'll need to consult with your own
 IP Lawyer, and almost certainly get permission from the Geographers' A-Z 
 Map Company.<br />
 (No database rights apply to the maps, as they were produced before such 
 rights were introduced.)
</p>

<a name="accuracy"></a>
<h3>How accurate are the locations you derive from the map?</h3>
<p>These maps were not drawn up using the national grid, so we have to
 convert the co-ordinates from them.</p>
<p>For the Geographers' Authentic Map of London, the map is laid out with
 1/2 mile grid squares. These grid squares appear to be at a slight slant
 to the OS National Grid, and also appear to be a tiny bit too small.
 The slant doesn't appear to change over the map, and our best-fit parameters
 for the slant and scale give a typical error of under 200m.</p>
<p>For the Geographers' 6 Inch Map of Central London, the map is laid out
 with 1/4 mile grid squares, centred on Charring Cross. We have yet to
 investigate the tilt or scale of these.</p>

<a name="scans"></a>
<h3>Could I get a copy of the scans?</h3>
<p>We would be happy to provide copies of the scans. However, you will need
 to seek a licence from the Geographers' A-Z Map Company first. Let us
 know once you have a licence from them, and we can send you the scans.
</p>

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