In the Einstein Tower the construction containing the optics consists of two wooden platforms, each six m high, placed one above the other. The telescope has a lens objective of 60 cm diameter and focal length of 14 m. Rooms for observations and measurements are located at the base of the tower. In California the lab rooms are under each other; in Potsdam they are arranged horizontally. Another rotating mirror directs the sunlight to the spectrograph lab located in the basement behind an earthen wall on the southern side of the tower. It is about 14 m long and thermally insulated. Here is where the light is split up into its spectral components and analyzed. This design of a horizontal laboratory wing led to the elongated profile of the entire facility.