Theodolite that uses a magnetic compass to reference the measured directions to magnetic north. There are two type of boussole theodolites; those with a full compass that can be set up in any direction and those with a box compass that must be set up pointing to magnetic north.
In the United States and early in Europe all theodolites were boussole instrument in that they used a magnetic compass. The US instrument is called a Transit in the United States whereas the European instrument is called a theodolite. I have classed the military goniometer also as a Boussole instrument as it has a box compass.
Most of my Boussole instruments are from Wild Heerbrugg.