A rare model by H. Morin of 11 Rue Dulong, Paris.
This cross staff is of solid brass with German silvering.
There is a fine machine engraved continually adjustable vernier scale with multiple sights together with a droplet set square showing " H. Morin" when viewed through the sights. I have never seen one like this before.
The internal pendulum obscures sighting through the cross when the cross is not vertical and can be locked down for transit.
I have dismantled the cross to see how the pendulum worked and yes, I was able to re assemble the unit without a problem