Thread: Relevance?

We do this kind of thing all of the time and I can't think of anyone who has used erroneous numbers on purpose to simulate a "lack of knowledge because it's so old and they had things wrong back then so I have to make my map wrong as well". We always use the most up-to-date knowledge to make our maps modernly accurate but look as old and primitive as possible Human nature I guess. So post it up and I'm sure someone will be along to point out any errors but in a friendly way (we're not much into the old "I'm smarter than you" kind of thing here). These old-looking maps are very popular for folks to hang on walls and put into fancy frames so try it put and if you get stuck we'll be here to help.

I can't read the numbers but I suspect they are correct. As far as I can tell, the longitude and latitude lines depict an azimuthal equidistant equatorial projection, also known as a stereographic projection http://en.wikipedia.org/wiki/Stereographic_projection

The map might be made up inplaces, due to lack of knowledge or bad surveying, but the grid is valid. I've used it on a couple of maps.
-Rob A>

Thanks guys. Rob, here's a closer view of the numbers along the top (which are mirrored at the bottom)

Originally Posted by RobA

I can't read the numbers but I suspect they are correct. As far as I can tell, the longitude and latitude lines depict an azimuthal equidistant equatorial projection, also known as a stereographic projection http://en.wikipedia.org/wiki/Stereographic_projection

The map might be made up inplaces, due to lack of knowledge or bad surveying, but the grid is valid. I've used it on a couple of maps.
-Rob A>

The latitude and longitude lines used today are depicted as 15 degrees apart. so, instead of having the numbers labeled by 10s you would label them by 15. Also the the Prime Meridian is set at 0 degrees and instead of labeling them by 10s up to 360 it is labeled by 15s up to 180 in each direction. It also labels the tropics and the arctic/antarctic circles at 23 1/2 and 66 1/2 degrees respectively.

Its difficult for me to explain, but this picture may make it more understandable http://www.mapsofworld.com/world-map...longitude.html

Excellent, thanks Slylok. Once i've begun pulling the designs together, i'll post them up so you guys ca give them the once over.

Thanks again!

Those numbers are correct. What you have there is a pair of equatorial aspect stereographic azimuthal projections (At least I'm pretty sure that's what it is.)

Now the placement of the features on the maps is obviously not particularly accurate as it's off by thousands of kilometres, but for a map of that scale, the coordinates mean exactly the same thing on that map as they do on a modern one. You have to be dealing with a much larger scale before you have to worry about differences in the datum.

Put another way, the people back then may not have had a very good idea of what shape North America was, but their idea of what 45° North means, was very very close to what ours is and the differences wouldn't be remotely visible on a map of the whole world regardless of the projection.