Troughton and Simms with Compass

This is an interesting theodolite with a whole circle compass on the base plate. Typically the T & S theodolites incorporated a trough compass as it was more accurate with the longer compass needle.
The wooden case is also different as it is designed to be opened standing up and the theodolite is removed using a sliding wooden base similar to a couple of instruments in my collection from the USA.
The compass also bears the inscription that the unit was made for B. Peterson & Co  in Christchurch. This jeweller started business in 1863 and left Christchurch in the late 1860s and established a business in London. When Peterson left Christchurch he sold his business and the new owner retained the Peterson name.
The current business has been sold a few times but even to this day retains " Peterson" in part of the name.
I have made extensive enquiries to try to ascertain when "Peterson & Co" was in operation but cannot tie the period down.

Circa mid 1860s