Benjamin Cole Sr. (1695–1766) was an English surveyor, cartographer, instrument maker, engraver and bookbinder living in Oxford. Benjamin Cole Jr. (1725–1813) apprenticed for his father in 1739. In 1750 Benjamin Cole Sr. & Jr. formed Cole & Son. In 1766 when Benjamin Cole Sr. passed away, the firm became known as Benjamin Cole again. John Troughton took over the Cole business in 1782, which was the start of the famous Troughton firm (later to become Cooke, Troughton & Simms).

Benjamin Cole Sr. apprenticed for a well-known instrument maker, Thomas Wright. Cole Sr. is believed to have opened up his own business between 1733 and 1739, and then partnered with his son around 1750.

The Coles were a prominent instrument making family in the mid-18th Century, which is when English makers really started to take over the instrument making business worldwide (largely on the basis of better telescopes). While many English makers exported instruments to other countries, the Coles really seemed to target the export market, especially America. I was surprised to find a fair number of Cole Theodolites while researching the instruments used by Colonial Americans. And, according to Bedini, George Washington used a Cole Long Telescope at Mt. Vernon.

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 recall reading 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.

The ad regarding a "new" Cole Theodolite stolen in Pennsylvania in 1770 (see ad at the bottom of this webpage) muddies the water a bit however. "New" might just mean "new" to America rather than a made in 1770 instrument.