ABSTRACT
In the latter half o f the 1920s Wilhelm Cauer (1900-1945) developed his plan for an electromechanical machine to solve linear equations. By the end of the next decade he would be acquainted with four similar projects which had emerged autonomously in different parts o f the world. These other machines differed from each other and from his in both concept and technological realization, but they all were capable of calculating com plicated formulas in one step or in an automatically performed sequence of steps. Together they can be seen as representative elements of the pre-history of the stored-program computer. They confirm the existence of a growing demand for calculating machines which could exceed the capabilities of contemporary desk top calculators to add and multiply. They indicate that some common aspects of the scientific-technological world produced identical questions and problems on the European continent, in Great Britain and on the other side of the Atlantic, in spite of considerable differences in cultural and political situations.
