Circa 1750 Improved Theodolite - Owned by the Surveyor General of Vermont - Used to Survey U.S. and Canada Border
Collecting Improved Theodolites
Early Improved Theodolites (aka Altazimuth Theodolites) are spectacular instruments - they were the top of the food chain of surveying instruments in Colonial America.
Given America's vast amount of heavily forested and uncultivated lands, the magnetic compass was the tool of choice for most of the surveys that happened in Colonial America. But there is evidence aplenty that Improved Theodolites played a role in surveying Colonial America.
NOMENCLATURE
Improved Theodolite - Developed around 1725 with an illustration contained in Wyld's 1725 book on Surveying. Called an Improved Theodolite in Hammonds 1731 book on Surveying, which featured a neat illustration as well. An Improved Theodolite could measure vertical angles as well as horizontal, and featured a telescope. From 1725 until the early 1800's, these theodolites were often called an Improved Theodolite or a Telescopic Theodolite (or some version of that). After the Improved Theodolite dominated the market, sometime around 1800 or so these instruments became known as just "Theodolites". Later on, they would sometimes be called "Altazimuth Theodolites" by Museums and collectors.
See the 1982 Whipple Museum Catalogue (Catalogue Cover) for a really good explanation of the term "Improved Theodolite".
If you are researching these instruments, just search for "Theodolite" and you will pull up almost everything. You will also pull up more recent instruments, but it is easy to sort them out with a glance.
For the sake of clarity here, I'm calling all of these telescopic theodolites that can measure vertical angles "Improved Theodolites".
Why Did Colonial Americans Import Improved Theodolites?
Improved Theodolites had four meaningful advantages over magnetic compasses: Improved theodolites could measure independently of the magnetic needle, were more precise because they generally had verniers that could measure to the nearest 10 minutes or so, offered longer range sighting when the telescopes were employed, and they could measure vertical angles. On the downside, Improved Theodolites were MUCH more expensive to buy and maintain, were more fragile, and took longer to setup and use than a magnetic compass.
In sum, Improved Theodolites offered the promise of much more precise surveys, but at a very significant cost.
Given the trade-off between precision and cost, Improved Theodolites were likely used mostly in surveys requiring a much higher level of precision than a magnetic compass or even a Simple Theodolite could offer - like Boundary surveys, or surveys of large wealthy landowner estates.
How Many Improved Theodolites Were Imported Into America?
Nobody knows, of course, but I suspect that a good number of Improved Theodolites were imported into the America. I found 6 Improved Theodolites that were used in Colonial America while searching the internet for a few hours. To me, that suggests that there were quite a few that were likely used here.
Thomas Jefferson was a Man of Science, and now doubt wanted the best instruments he could get his hands on. He had more than one Theodolite, and the last one was made by Ramsden.
A very cool Improved Theodolite owned by the Surveyor General of Vermont and used to survey the U.S. and Canadian border. Owned by the National Museum of American History.
A wonderful Improved Theodolite made by an unknown maker. Owned by the National Museum of American History.
The John Lukens Improved Theodolite
John Lukens was the Surveyor General of Pennslyvania. The newspaper clipping above is a 1790 listing of his Estate Sale. Lukens owned an Improved Theodolite and a number of Simple Theodolites when he passed away.
The S. Gale Improved Theodolite
The above is a newspaper clipping from 1770 offering a reward for various instruments that were stolen, including an Improved Theodolite
The Tunicliff Hotel Improved Theodolite
An Improved Theodolite is offered for sale in the above 1802 newspaper clipping.
Were Improved Theodolites Made in Colonial America?
Very few if any.
From the remnants of a compass made by David Rittenhouse, to is believed that Rittenhouse made at least one Improved Compass. The National Museum of American History also holds a Telescopic Theodolite made by Hagger of Baltimore - and dates the Instrument between 1816 to 1824. I think it might be a bit later than that. Either way - I think that is becoming a bit removed from the Colonial America Era.
Jeff Lock came across part of a David Rittenhouse Compass and determined that the Compass was actually part of an Improved Theodolite. The story is documented in the article that can be accessed thru the link above the pic.
An early Theodolite made by Hagger -Maker- Baltimore. Possibly made between 1816 to 1824, although I have seen a Hagger -Maker- Baltimore likely made sometime after 1824. Owned by the National Museum of American History.
Were Improved Theodolites Made Pre- Civil War in America?
Yes, although they were probably just called Theodolites or Telescopic Theodolites. It's possible that some of these theodolites were made in the UK and then rebranded when they came to America. I've seen telescopic theodolites "made" by Patten, Augustus Platt, and Pike. I suspect there were a few other American makers of Telescopic Theodolites
A Richard Patten Theodolite likely made before 1833. Owned by the National Museum of American History.
An Augustus Platt Theodolite likely made before 1843. Was located in Ohio in the 1960s. A bit more info can be accessed thru the link above the pic.
Benjamin Pike's Theodolite
A wonderful Pike Theodolite that is part of The Dale Beeks Collection. I will be offering this Theodolite, box, and tripod for sale in the near future.
Some Historical Improved Theodolite Transactions
There were very few theodolites made by American makers, so those instruments will always command a healthy premium.
Pre-1800 UK made improved theodolites are fairly scarce, and based on what I have seen you should expect to pay $1500 on up depending on quality, the maker, extra features, and age. UK theodolites made between 1800 and 1850 pop up every now and then and can typically be had for $1000, give to take. UK theodolites made after 1850 are fairly plentiful and can me had for $500 or so.
Below are a handful of the more interesting offerings I came across.
Early 1980s Antiquarian Scientist Ad
1984 Tesseract Ad
1985 Antiquarian Scientist Ad
Mid 1987 Moskowitz Ad
2003 Christies Auction
2015 Tesseract Ad
2016 Auction
2016 Auction
2019 Auction
2020 Auction
2020 Auction
2021 Auction
Final Thoughts on Collecting Improved Theodolites
Like many surveying instrument collectors, I love instruments made and signed by American makers. But thanks to the internet and the digitization of books, newspapers, instrument catalogues, and pictures, I have a growing understanding of and appreciation for foreign made instruments (like the Improved Theodolite) that were used by surveyors in America. I personally think that Improved Theodolites have a place in a well developed American surveying collection.
Plus, let's be honest…Improved Theodolites are pretty dang cool. And the UK-made instruments are fairly affordable based on the most recent auction results.
If you want to see some amazing Theodolites, go to the UK Science Museum Group and search for Theodolites, or Click Here.
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