TrigPointing

[wayn0]

TAS
SURVEY CAIRNS, JAMES SPRENT AND THE TRIGONOMETRICAL SURVEY OF TASMANIA 1833 - 1855:
https://isaust.org.au/resources/newsltr ... surv59.pdf

Great article. I’m looking forward to my next Tasmania visit even more now.

I love that map! If you have found/find more things like that, please share it here so we can all enjoy it.

That's very very cool about the old surveyor. I'm keen to see your pics when you eventually get to the one he's mentioned to you.

I have a thing for old maps. For example I have dozens of old military topo maps that provide many adventure options, including trig locations. Unfortunately by the 1990s most maps stopped showing control stations, at least in Queensland. Search for maps between 1940s-1980s. Not all maps show trig locations but most military topo ones do. The Australian Military had Topographical Survey Squadrons. When WWII started there was a call for a war-survey. There became a need to know our terrain more accurately, particularly in northern Australia, so of course trig stations were highlighted, and many installed during this time.

From Military Topo Map, 1945



The old trig cairn from 1880s is still going strong. Easy to get to as well.

Mount Mia (original)



Happy New Year geo-friends and safe caching for 2023

[Now_To_Morrow]

I love finding the older ones that haven't been completely removed and replaced by newer ones.
I found this magazine article in Trove from 1833 mentioning a number of the trigs already existing in NSW before it was written, and the need for many more. I doubt any evidence of the original versions exist today. If so they would be around 200 years old.

https://nla.gov.au/nla.obj-765171557/vi ... gonometric

[wayn0]

Great find! That was interesting reading. "three male convicts for every mile of road he shall contract"

Kind of off topic but relating to this..

The broad arrow symbol we have all seen around the place either carved on blazes or rock or trig posts etc, was first used by the Board of Ordnance in England. They were mostly a military thing but land surveying and eventually map making (Ordnace Survey) followed. This of course involved trig stations. Back to the broad arrow symbol, it wasn't just used to represent survey goodness, it was first used in England and later in British colonies to mark government property.. this included convicts who ironically were utilised to clear land around survey points and routes to them.


Port Arthur convict uniform

The exterior side of the trousers is printed with a broad arrow stamp identifying the trousers as well as the convict as government property.

[Now_To_Morrow]

I had likened the arrow to stereotypical convict uniforms but had never made a connection. Well there you go! I was wondering what they meant as they don't point north. Yesterday I was looking at one stamped into a trig vane puzzled by it still. Thanks for sharing that. Definitely on topic in my books.