§         a smaller quadrant, graduated from 0 to 90 degrees (each division equal to half a degree) and hinged under the circular quadrant which bears on the upper side the words Elevatio Aequatoris, and which, thanks to a system of freely moving hinges, always places itself in a vertical position, and a small weighted wire that almost touches it allows the reading of the inclination of the plane of the circular quadrant with respect to the plane of the wooden base.

A rod (with a notch at one end and a peg at the other) is fitted above the circular quadrant; this holds a staff fitted with a second staff (alidade) at opposite ends of which there are a small converging lens and a small screen with a small circle etched at the centre; the alidade can freely rotate 360 degrees parallel to the plane of the circular quadrant and about 30 degrees perpendicularly to it.