This is an incredibly small and very cool Dudley Adams Theodolite that measures angles via a vernier scale to 3 minutes.

Take a look at the first two pics below. The first pic compares the Adams Theodolite to a full size Seelig Transit that I have. Wow. The second pic I compare the Adams Theodolite to a Lietz transit that I have. The difference in size here is very significant but not eye-popping. Except…the Lietz transit is actually a miniature Circa 1902 Lietz Preliminary Transit I have offered for sale. I amazed that the English could make a Theodolite that small around 1800 or so.

Miniature surveying instruments involve trade-offs. The telescope doesn't add much range and the engraved numbers are hard to read, especially for older eyes. While the Adams suffers from those trade-offs, the Adams looks and feels like a real surveying instrument albeit in miniature form.

The main issue with the Adams Theodolite - one of the standards has a crack in it. I didn't see the crack until I focused on the pics - so the crack doesn't jump out at you while viewing the instrument. You can see the crack at the base of the right standard in the very top pic above and the very last pic below. The crosshairs in the telescope are also missing.

Miniature instruments are really neat, and the Adams is one of my favorites given how tiny and old it is. The Adams would be wonderful on display, especially when placed next to either a full-size or small size American Transit.

If you are interested in a bit more information about Dudley Adams and the instruments he made, please see my Adams Family Maker 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 Adams 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 the Adams Theodolite.