My Cole Theodolite is a wonderful instrument. On its wood base, this might one of the best display instruments that I have ever seen.

This is a top-end early Telescopic Theodolite. For starters, the Telescope has two adjustment mechanisms - one to control focus and the other to control the focus of the crosshairs. I don't recall seeing any other early Theodolite that had an a way to focus the crosshairs.

The Vertical Arc control mechanism is also top-end. The mechanism contains a reduction gear, giving the surveyor wonderful minute control over the movement of the Vertical Arc. Wow.

The overall build quality and workmanship of the Theodolite are, not surprising, top notch. and the presentation of the instrument - on a wood base that contains holders for the sight vanes, a small tool up top and a circular protractor underneath (badly now missing) - is fantastic. I suspect Cole made this Theodolite for a wealthy individual rather than a roll up your sleeves surveyor.

I note the glass and needle on this Theodolite are not original.

It's hard to date Cole instruments (especially theodolites) since most instruments are signed "Cole Fecit" This could be circa 1735 to 1750 when Cole Sr. operated the business under his own name, or circa 1750 to 1766 when father & son partnered, or from 1766 to 1782 after Cole Sr. passed away and Cole Jr. ran the business.

One possible clue might be the vernier scale on the Theodolites singed "Cole Fecit". The Theodolites are fairly simple with horizontal vernier scales that read to 5 minutes. I understand that most English makers of Theodolites read to 3 minutes by the 1760s. So my best guess is that all of the Cole Theodolites were made in the 1740s and 1750s. This dating is also supported by the relatively simple design of all Cole Theodolites. For many early Theodolites the makers basically figured out a way to put a telescope on an existing 2 or 4 vane Simple Theodolite without chaining the entire design of the instrument. This Cole Theodolite falls into that category.

My Cole Theodolite is a really wonderful instrument, deserving of a really nice display. The fact that Cole apparently exported many Theodolites to America makes this Theodolite even more special for an American Collector.

If you are interested in a bit more information about Benjamin Cole Sr. & Jr and the instruments they made, please see my Cole Makers Webpage.


Finally, if you are interested in learning more about Theodolites made from 1500 to 1800, please see my Theodolites (1500 to 1800) Webpage. The Dollond Theodolite is what I call a Third Generation - Altazimuth Theodolite, so go directly to that page if you want to learn more about Theodolites made at roughly the same time as my Cole Theodolite.