The Orbis Blog

The Invention That Changed Surveying

In the world of timberland investment assets, firm and clear boundaries are everything.

That’s because timberland investments are like any other investment class – they hold the promise for a good rate of return.

When it comes to timberland assets …

Acreage Can Equate to Profitability

With  ~105 million acres of investable timberland in the U.S., the potential investment return is mind boggling.

The truth is, land has always been a valuable investment, which means that properly parceling the land has always been an imperative.

Perhaps that’s why early land surveying mattered so much to the founders and early settlers of our nation.

Perhaps that’s why the land surveyors of the time are said to have literally defined America.

Perhaps that’s why we find early surveying such a fascinating topic even today.

But what really matters to us now is the how early surveyors did their jobs.


Because the then-new technology known as the surveyor’s chain, is still having a profound effect on this country’s timberland investment assets. (See this post and keep reading to learn more.)

The Mathematics of Measurement

So what, exactly, was this “new” invention and, more importantly, how did it change surveying?

According to Encyclopedia Britannica, a surveyor’s chain is a “measuring device and arbitrary measurement unit.” Britannica cites Edmund Gunter, a 17th-century mathematician with inventing the surveyor’s chain, also called Gunter’s Chain.

While the Land Ordinance of 1785 did mandate that all official government surveys be done with Gunter’s Chain (that meant all the states West of the original 13 colonies), Gunter wasn’t the only chain inventor – he just happened to be the inventor who had the chain that made the most mathematical sense.

Gunter’s Chain was “embedded in the foundation of our land system,” says Timothy S. Guisewhite, PLS.

Because landowners needed to determine property boundaries long before GPS, GIS and aerial photography, the only way to do so was the proverbial boots-on-the-ground method of walking the property and measuring the perimeter.

Gunter, who’s the focus of our discussion here, had his own idea for the surveyor’s chain: Creating a practical method for decimalizing the acre. That’s why Gunter’s Chain contains 100 links and is precisely 66 feet in length – resulting in an area of 10 square chains equaling one acre.

While that may sound elementary to us today, it was revolutionary at the time as:

  • Gunter’s Chain lessened the possibility for error because it could be used in either direction whereas Rathbone’s chain had a forward and back end that could be confusing,
  • Gunter’s Chain made converting chain-and-link measurements to acres simple and easy.
  • Gunter’s Chain made measuring irregularly shaped properties more accurate than other chain methods.

Voila! Modern measurement mathematics.

Chains, Marking Pins and Tallies

Once Gunter’s Chain came along, historical surveyors needed only two addition things to survey the land: marking pins and a tally belt.

The surveying process involved a head chainman and a rear chainman walking and pulling the chain to length, placing a marking pin, and then picking up and counting the pin after the next one was placed. Then lather, rinse and repeat, as they say, until the area was measured.

What’s especially interesting is that the remnants of these chain measurements are still found in today’s land records :

While Gunter’s Chain was far more accurate than other types of surveying chains and methodologies, it’s important to note that measurements done decades ago – even with Gunter’s Chain – can still contain measurement and miscounting errors. It’s simply the nature of human error in counting and rounding up or down, as well as external factors, such as worn-out chains and slope distances.

Which brings us full circle to timberland investment returns.

What do you think?

Can decades- or even centuries-old surveying methodologies have an implication of the accuracy of today’s land records? Do you trust the old chain system? Share your thoughts on the pros and cons of the surveyor’s chain.

Leave a comment to join the discussion.

This post is part of a 5-part series on the history of measurement  and its implications on timberland investment assets. Find the other posts in the series here:

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