ORDNANCE SURVEY Maps & Major-General Colby:

Thomas Frederick Colby FRS FRSE FGS FRGS (1 September 1784 – 9 October 1852), was a British major-general and early director of the Ordnance Survey (OS).

 A Fellow of the Royal Astronomical Society and Royal Society, Colby was a Military Career officer & one of the leading geographers of his time.

He was a key figure in the ordnance survey mapping of all the UK and Ireland .. being single-handedly responsible for the very first Ordnance one inch to the mile series -  because he lost his left hand in December 1803 aged 19 - when a pistol he was shooting blew-up.

 He lived the rest of his life with a part of that gun lodged in his skull.

You guys will likely already have noted the military implication of the name ORDNANCE ... relating to cannon and artillery. - This detailed 'close-up' series of maps of Britain was made by military men for military reasons - to guide on artillery placement and 'gun laying'.

All entries about this man read the same .. and there seems to be but the one image. I tried my best to get more detail about the pistol blowing up - but all I can find is that the gun may have been loaded with shot when it KABOOMED in Liskeard Cornwall - and it likely was one of a pair loaded & handed to him by someone else.

The amputation of his left hand must have made manipulating survey instruments a hell of a task ..

Link: https://en.wikipedia.org/wiki/Thomas_Frederick_Colby

And I've found a brilliant BBC video "A VERY BRITISH MAP"

https://www.youtube.com/watch?v=w5_kWzUahQU

The "One inch Ordnance Survey" maps became much loved and widely used in UK .. part of their value was that while they were the most accurate and detailed records of the country side for travelers - they were also hand drawn and colorful works of art from a time way before computers and aerial surveys.
Marty K.