Hello all, I am a rare materials cataloger who occasionally does maps, and I struggle sometimes with determining scale. I am currently working on a 1868 map with a bar scale in English miles. I found a record that gives an approx. scale of 1:57,217, but I can't figure out how they came to that number. The bar scale measures approx 2.3 in, with 1 inch approx 2.25 English miles. When I compare 1 mile against the NSI I get a scale somewhere between 140,000-145,000, so I have no idea where the number 57217 comes from. I will try to attach some pics of the bar scale. Any help would be appreciated. Thank you -Silvana