Since the theory of General Relativity has existed, the corresponding question has been discussed as to whether and to what degree Newton's theory of gravitation can be considered as a special case or, at least, as a limit situation of General Relativity. In the 1920s, E. Cartan took a very important step to a better understanding of this limit process. He formulated the Newtonian theory as a field theory on a four-dimensional manifold. In the 1980s, Jurgen Ehlers developed his frame theory and gave an answer to the question to which extend the transition from Einstein's theory of relativity...