Added in 1921/24, the 16 meter-high Einstein Tower is well known in its own right for being an example of expressionist architecture, being designed by the famous architect Erich Mendelsohn. Earlier, Schwarzschild had attempted (obviously unsuccessfully) to measure the redshift of Fraunhofer lines in the gravitational field of the Sun, as predicted in Einstein's theory, from the previously-mentioned solar observatory. The Einstein Tower was constructed to further research in this direction, thru the initiative of the physicist Erwin Finlay-Freundlich (who had been collaborating with Einstein, especially after Einstein had moved to Berlin in 1914 to work for the Academy of Sciences). Because of the sky-high inflation prevailing in Germany during construction, the original plan for reinforced concrete had to be abandoned and it was built in brick covered in plaster. The financing was dependent on private donations - the cost for the optical instruments was borne heavily by Carl Zeiss Jena. Needless to say, the tower had little success in its original purpose of detecting the gravitational red-shift but served as an important solar telescope in other work, for example - the measurement of magnetic fields in sunspots and investigations of the corona. It was severely damaged in a bomb attack of 14. April 1945 and it was some time before research was able to fully get started again.