PHOTO: Dennis Firth shows the tree with the surveyor’s mark – which begged the question ‘what does the 23 refer to?’
By LIAM MULHALL
Living in a town formed in the late 19th century, you can occasionally be lucky enough to come across some living remnants of history in Coonamble.
This was the case for Bill Corby and Denis Firth, who discovered an old ‘reference tree’ in a paddock across the railway line near the Coonamble cemetery.
Used in the early days of property surveying, a surveyor would engrave a marking into a suitable tree located away from a boundary corner stating information ranging from bearings, distances, or plot numbers which would direct a person to the relevant boundary corner.
In the case of the tree west of Coonamble, the number “23” is engraved into the south side of the trunk, with an arrow pointing due north.
After much discussion with former Coonamble Shire engineers, surveyors, and a Past President of the NSW Country Surveyors Association it has been resolved that the 23 is in reference to the plot number, and the arrow, the direction towards its boundary corner.
Nowadays, surveyors more commonly use 300mm long galvanised iron pipe, placed at least 80mm below the ground.
Registered Land Surveyor and Director of Compass Consulting Surveys Eric Smith explained that trees were convenient for surveyors to use.
“They used trees because they were easy, normally a big box or gum, pretty stable a tree like that,” he said.
“Trees could actually still be used today, although it was phased out in the 1970s.
“You can see trees from a mile away, but they can fall over, burn, be eaten out by bugs, or damaged, so it’s better to use more modern techniques.”
Mr Smith estimated that the reference tree found in Coonamble was put there in the mid-20th century.
“It’s just a guess, but I would say it’s maybe from the 1950s or 60s, but it could be older than that,” he said.
“It’s a beautifully carved tree.”
However, reference trees are becoming “rarer and rarer” to find in the current day thanks to changing land use.
“In areas like Coonamble trees will often get cleared out by a bulldozer and the people doing it won’t realise that it’s a reference tree,” said Mr Smith.
“Not long ago I was out at a property in Gundabooka near Louth, and was out looking for some and they had all been cleared out.”
In New South Wales, if you accidentally or purposefully remove or damage a survey mark you may be liable for up to $10,000, and that’s before costs associated with surveyor fees.
Eric Smith says one of the interesting things about the old reference trees, is how accurate they can be despite their age.
“Not long ago I was out looking at an old tree that was marked in 1886, and using an old map of the plot boundary I found the corner boundary,” he said.
“When I looked at it, I couldn’t believe it, but there was a pile of rocks to mark the boundary corner and it was within eight millimetres of the supposed distance from the tree.”