Equatorial mountings: The German mounting
 
There are several designs of equatorial mounting, perhaps the most commonly used for refractors being the German mounting which is illustrated in figure 1. The declination axis is in the form of a beam across the top of the polar axis. The telescope is fixed to the end of the declination axis and the mounting requires a counterweight at the opposite end of the axis so that the system is balanced over the whole range of hour angles. Although the German mounting gives rise to larger stresses in the bearings and shafts than other designs, it has advantages in its ease of operation over the whole of the sky. It can easily be seen that for every point in the sky, the telescope can be set in one of two positions which are separated in hour angle by 180^◦.

Figure 1. The principle of the German mounting.