[OSM-talk] OS maps circa 1900 wanted, will contribute to scanning cost
bareman at tpg.com.au
Sat Mar 31 03:26:24 BST 2012
On Fri, 30 Mar 2012 10:48:47 +0100
Lester Caine <lester at lsces.co.uk> wrote:
> mick wrote:
> > Does anyone on the list possess the set of Ordinance Survey maps of England, Scotland& Wales of about 1900, I'm trying to map the Roman roads described by Thomas Codrington in his book "Roman Roads in Britain" published in 1903. He makes frequent reference to "the new OS map" in his descriptions.
> Not off topic at all really, as many of us want some mechanism for easily
> managing secondary layers. However MANY of the roads you are looking at in that
> book still exist today and so just need a valid 'start_date' attaching. I have a
> growing collection of maps going back into the 1800's but only an A3 scanner
> which is not ideal as it has a lip around the scanning area :(
> Lester Caine - G8HFL
Unfortunately when I asked earlier for help finding info about Roman roads and such, there were a few on the list stating the idea was totally offensive to them and I also received several flames of list.
I guess, based on a map I trace, there are about 10% by length of them already on the map flagged as roman_road. There are about 30% more that are very close to existing roads, these are probably on, or slightly realigned from the actual course of the roman roads and my tracing lacked adequate accuracy. For example Roman Ermine Street is substantially the same shape as the modern one so I suspect my tracing has moved it a little bit to the west.
My current procedure is to mark what I traced as tentative and then as I find further sources increase the confidence value. I have been adding start dates where I can find them.
I have tried to scan the Australian equivalents of the OS maps on an A4 scanner and not had much luck,fortunately I have been able to download the complete set as shape files. That was why I offered to contribute to scanning costs.
Ordinance Survey does a great job of making the current set for England, Scotland & Wales available as shape files but the availability of historic digital maps fall far behind, being commercialized and doled out in tiny chunks using a proprietary format, fine for people planning a day hike to transfer to their GPS but very expensive to get wider coverage and then you can't get it out in any useful format without paying extra for the uncrippled version of MemoryMap.
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