To work, this instrument's dial has to be parallel to the equator and, when the sun is exactly over the equator, it gives the time of the equinoxes, hence the two names of this clock.
The position of the dial can be adjusted according to the latitude of where the measurement is taken, which is why these types of sundials were so universal. The maker, Andrea Vogler, worked in Augusta in the second half of the eighteenth century
Orologio solare detto equatoriale
o equinoziale, firmato Andrea Vogler XVII secolo