In 1936, in the UK, trig points (or triangulation pillars) were used by the Ordnance Survey in order to determine the correct shape of the country. The actual trigs themselves are mainly 4ft, concrete pillars. Source
My dad was a complex man but as kids, he introduced us to what is now commonly called 'trig bagging, ' ie searching for trigs across the countryside and recording them, for no apparent reason! You have to be a nerd to understand.
On the top of the trig, you’ll find a metal disc with three grooves where the theodolite would be sitting. The telescope in the theodolite would be pointed at the next trig point. The angles would be used to calculate the exact location of each trig point, which in turn would build up a map of the country.Source
Unfortunately, the trigs are usually at the highest point in the area but it wasn't too steep today. I hate walking uphill as I forget to breathe, which isn't very helpful!
Even though trigs are now obsolete, as we have GPS, they still come in handy for hikers as a kind of waymarker. They are also the right height for pooches to piddle up!
Anyway, we returned from our little walk with another trig bagged!
Interesting! We never found one of these during our hikes in the past.
That's a shame. They're not much to look at but interesting nonetheless.
play it cool Trig
😁😉