Prompted by a documentary I saw recently, I have in front of me a map of the environs of where I live. What makes me a dinosaur is it’s not on a satnav, or Google Maps. A good old fashioned paper map produced by the Ordnance Survey.

This outfit was formed in the 1800s with the specific intent of mapping the South Coast so if Johnny Foreigner (in the shape of Napoleon and his merry men) invaded, defending artillery would know exactly where the invaders were and could hence shell the crap out of the perfidious French.

Like Topsy, the project growed and growed, and the whole of the British Isles got mapped in huge detail. On a current Landranger (1:50000 scale), somebody pointed out that if you move just a few metres from your front door, you’ll appear on an OS map if you stand still long enough.

The OS is acknowledged as the world authority on map making, and just about every country in the world uses its painstakingly developed techniques. Originally these relied on men wearing jackets and ties triangulating the country, and using theodolites to calculate altitudes and hence contours. Like Gerry Anderson’s team, they were often to be seen with a pipe in their mouths.

Back at the ranch, it took a year or so to learn how to prepare the copper plates used for printing, and it took a long time to do that too. Lots of stuff is digital now, but back then it was, ‘Break out the log tables, and roll your sleeves up.’

An OS map is both a thing of beauty, and a thing of great utility. I know. I was taught to read one in school, then honed my skills in the Army Cadets. I still know the symbols for, say, a railway cutting (as opposed to an embankment), or a tumulus (more prosaically called a ‘Mound’ these days), a church with a spire…

I can look at the contour lines, and judge how long I need to add for a hike as it goes up and down. I can still calculate how to deal with the difference between grid north (ie map north), magnetic north, and true north.

If I had to I could give you a six-figure grid reference that would get you to within 10 metres of where you want to be.

However, just as with Google maps (but much much less frequently), even the OS cocks things up. When I did a goodly amount of amateur rally navigation, generally at least one map I used in a night would have a bloody great red marker circle on it, and the acronym NAM, ie I’d discovered a particularly tricky junction or bend that was Not As Map.

OS maps don’t just get you there. They tell you what’s around you, why you should go one way and not the other. This is where it’s a million times better than pratnav.

BTW, want to know where military installations are on an OS map? Look for areas where there’s no detail of what’s on the ground. Those details were/are not included. Just look for Chatham Dockyards.