Frequently Asked Questions

How accurate are the maps?

Pretty accurate! The maps were made by professional surveyors using the best technology available at the time. In the 1740s, when Rocque was making his map, this involved using a "Waywize" - a device with a large wheel, a bit like a wheelbarrow, that was pushed over every street. The wheel had a circumference of 8' 3" - one 640th of a mile - so by counting the revolutions distances could be recorded.

The maps were then drawn at the chosen scale, sometimes as large as 26 inches to the mile, and printed on multiple sheets. The images that have been scanned for TTX sometimes come from different editions and in any case paper stretches and distorts over 250 years. So one of the challenges is that individual sheets do not necessarily align properly with their neighbours leading to discontinuities in the scanned images.

The final problem is that, oddly, the original surveyors did not draw these maps with the intention of ensuring legibility when zoomed in on a screen. If they had a name in a small alley, they would simply use a very small font. Contrast this with the modern maps designed for interactive display and you see that the roads are consistent widths with very clear fonts. Even here, however, there is compromise. If you look at Google or Bing maps in hybrid mode, showing both the satellite and map view, you will often find that the roads have been simplified and straightened for legiblity rather than geographic accuracy

Why has the River Thames changed?

One of the major developments in Victorian times was the building, between 1865 and 1870, of the Victoria Embankment. This served two purposes: it eased traffic between Westminster and the City by providing an alternative route to Fleet Street and the Strand. Perhaps more importantly it enabled London's sewerage - which until then had been emptied straight into the river - to be piped down river and out of the city. At a stroke this eased congestion and the stench.

The work meant many of the old wharfs and riverfront businesses were replaced with fine buildings - and the river was significantly reduced in width

Why can't I see points of interest on the map?

Assuming you have points of interest enabled (no red cross through the top left icon) it may be that you have too many POIs to display. There is a limit to how many it makes sense to show on a single screen and a message pops up briefly to warn you. You can show POIs by zooming in or, often, by dragging to an adjacent area so there are fewer POIs to display.

Why is the app so big?

You can't skimp on quality! TTX is a large download. Besides the app itself the download includes full details of 750 points of interest, 150 audio guides plus a further hour's worth of audio tour information, 1500 photos and an initial map stored in great detail. We chose to bundle all these with the app so that once it is installed you can use it immediately without depending on network coverage or the cellular network.

This is particularly important for our overseas customers who may be paying costly roaming charges. For the same reason, when you buy additional maps you can download them via wi-fi and store them on your device.

So although the download may take several minutes, it will be worth it.

How can I get hold of the maps?

The high-quality scans of the London maps - Rocque (1746), Horwood (1799), Greenwood (1830) and Stanford (1862) - are provided under license from MOTCO Enterprises Ltd. For more information, copies of the maps on CD or printed reproduction please visit their site.

Where can I find out more?

The written information in TTX has been checked for accuracy by a professional Tour Guide who has been awarded the Institute of Tourist Guiding's Blue Badge, the highest level of accreditation. She also recorded the audio tour information.

If you would like to find out more about Tour Guides and arrange a car, coach or walking tour please visit Tour Guides Ltd or Touristguides.org.uk.