OK, you almost got it right... we arrived here in 1786 (the Niagara peninsula)
from the Albany area (look up the town of Ball's Falls on the map, that's us). Sometime prior to that, the Worcester area of western England.
This device, however old it is, was
last used by the brother of the clerical fellow whose picture sits above my mantle... this would be in the 1870s. I find it hard to do the maths - hell, any logical reasoning - at this time in the morning, but methinks, GG Uncle?
I hasten to stress that the pic referenced above shows an octant missing most of its bits... mine is
complete.
