The recent blog post on Map Type Comparisons which compared a 1km grid square around Helvellyn on eight different Ordnance Survey map types proved very popular. It also brought up the two other topics – urban mapping and historical mapping. This blog post deals with the historic mapping.
I won’t cover it here, but the history of map making is quite something. Just think back before the advent of GPS, and most of us then start to think about the famous trig points. However, go further back, and it gets even more complex. The facts that the original maps ever got made is quite a testament to the early map makers.
Whilst the original blog post concentrated on a 1km square, for this comparison, due to the mapping not being as detailed, I have moved the sizing to be a 3*3 km square.
The maps shown below are OS 1805-1974, OS 1896-1904, OS 1919-1926, OS 1945-48 and finally OS Landranger from December 2016.
I find a number of thing interesting here. The first map took from 1805 to 1874 to make, which is 69 years, whilst the post war map took from 1945 to 1948. The grid lines only got added in the inter-war map.
Looking at the post-war map, it’s also very visible that this is two maps stitched together. When these maps were digitised, they were recalibrated and matched up, and its plain to see the loss of accuracy in a circa 1945 map by just looking at the grid lines.
OS December 2016