TrigpointingUK

Hello,
I have a 1920s Ordnance Survey one inch map of Chichester and Worthing.
On it there is a little trigpoint symbol on Sathill Road (north of Fishbourne) next to ‘South Oak’.
Here’s the link:
https://maps.nls.uk/view/239259829
On a slightly later map (still before trig points) it says ‘trigonometrical point’.
Could these be the forerunners of trig points?

Thanks. A reply would be appreciated.

Almost certainly a trig station from the original 19th C triangulation.

Thank you! This has been on my mind for months.