Precious field books part of enormous heritage project

More than a million pages from thousands of surveyors’ field notebooks dating back to the mid-1800s, as well as early survey plans and native land title records, have been digitised in one of the largest cultural heritage projects in the world.

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Land boundaries and land ownership in New Zealand is determined by a system of survey records called the cadastre (or cadaster).

The early Romans first introduced the idea of a cadastre for taxing landowners. The Domesday Book from 1086, which is the oldest public record in England, was an early cadastre for England so that King William the Conqueror could levy taxes.

Mike Morris is Principal Cadastral Surveyor at Land Information New Zealand (LINZ). He is in charge of making sure that the New Zealand digital cadastre is kept up to date, and he says that “we are very lucky to have a very accurate cadastre, which is a system for defining the extent of land.”

“Having an accurate cadastre means we can support the guarantee of title,” says Mike.

When you see surveyors measuring the boundaries between neighbouring houses, for instance, or marking out a new subdivision – all of that information becomes part of the cadastre.

Cadastral surveying is a specialised form of surveying, and in New Zealand it dates back to the 1840s.

The first surveyors in New Zealand included well-known explorers such as Thomas Brunner, Charles Heaphy and geologist Ferdinand Hochstetter. They usually worked for provinces until, in 1870, the state became responsible for guaranteeing freehold land titles.

But by the mid-1870s only about a third of the land had been adequately triangulated , and only 7% or so of the land had accurate boundaries. As a result, more and more cases of disputed boundaries and ownership were ending up in court.

In 1876, to solve this problem, the Department of the Surveyor-General - a predecessor of LINZ - was created and tasked with making accurate cadastral maps, for selling and taxing land.

Tools of trade

Tools of trade for early surveyors in the 1800s included a Vernier theodolite, tripod, a Gunter’s chain, and most importantly, a field notebook in which to record everything

A Gunter’s chain is a standard measuring device that was introduced in 1620. The chain is 20.117 m long and is made up of 100 links, hence the old measurements of chains and links. A cricket pitch is one chain long, and early minor roads in New Zealand were a chain wide.

The Vernier theodolite was levelled on top of the tripod. It had a telescope for sighting through and a circular protractor for precisely measuring degrees, minutes in a degree, and on some theodolites even seconds in a minute.

These tools enabled those early surveyors to triangulate, or take measurements of recognisable landmarks relative to a baseline. Permanent trig stations were gradually built as repeatable survey points.

“Surveyors in this era weren’t just surveyors,” says Mike.

“They were pioneers. They were adventurers. They would go out for months or possibly a year or more at a time.”

The surveyors meticulously recorded each measurement in field notebooks. When they returned to the office after many months in the field, they used trigonometry to map the location of points onto a survey plan.

Mike says that the field notebooks were more than just a very accurate data record. Some contained provisioning lists or notes about good fishing spots.

There were pencil and even watercolour sketches of landscapes, while some notebooks contained pressed flowers and even a four-leaf clover.

“There’s a couple of them that have got sandflies squashed in them,” says LINZ’s National Records Manager Alison Midwinter.

“It’s this window onto the life of a surveyor, who is out there in the backblocks with sandflies and mozzies buzzing around. It’s this connection to our incredibly beautiful, valuable historic past.”

Alison says that the original field notebooks are not just items of historical curiosity.

“The land record never becomes obsolete – people still use them,” says Alison.

“Sometimes you find yourself coming from the title you’ve got now right the way back, through the historical documents to the original plan … and the original field books.”

Digitising the old records

Back in the 1990s, LINZ created Land Online, which is New Zealand’s digital survey and title system. If you buy or sell a property – the title comes from Land Online.

A lot of the underpinning cadastral material was digitised, but by today’s standards that early digital information is low resolution and it is only in black and white. And there is still an ongoing stream of surveyors requiring access to fragile, early field note books that haven’t been scanned.

Alison Midwinter says that a significant number, but certainly not all, of LINZ’s historic records are now being digitised at high resolution as part of a very ambitious heritage project. It includes land titles from south Auckland, along with 15,000 North Island field notebooks, plans from parts of the North Island, and native land titles.

New Zealand Micrographic Services general manager Gavin Mitchell says that they have been working on the LINZ digitising project for a year using various pieces of scanning equipment. They have scanned over a million pages at high resolution, producing more than 100 terabytes of data.

Alison Midwinter says she is looking forward to having the high quality scans available for registered surveyors – and, in the cases of the field notebooks, the general public – to use. But that is certainly not the end of the original material which will end up housed at Archives NZ.

Where are the Pink and White Terraces?

The 1859 field notebooks of well-known geologist Ferdinand von Hochstetter have featured in a recent disagreement over the exact location of possible remnants of the famous Pink and White Terraces, on the shore of Lake Rotomohana, which were destroyed in the 1886 eruption of Mount Tarawera.

Historian Rex Bunn claims that forensic cartography, using survey measurements from the field notebooks, shows that any remnants of the terraces are located on land on what is today’s lakeshore.

Geologist Cornel de Ronde and colleagues from GNS Science used various methods to survey Lake Rotomohana between 2011 and 2014. In a new re-evaluation of their data they are confident that their results support maps published by Hochstetter in his 1863 geological atlas of New Zealand, and that what remains of the terraces are underwater.

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