[Berlin], 22 February [1895]. Rudolf Diesel's retained copy of his own signed manuscript letter to Samuel Breslauer, following up on previous correspondence concerning the installation of his prototype diesel engine, during the design stage. Text is in German. 4to. Single leaf, 4 lines of text on onion skin paper measuring approximately 30 x 24 cm. Minor age-toning, otherwise in very good condition. Rudolf Christian Karl Diesel (1858-1913), needing no introduction, was a German inventor and mechanical engineer who is world-famous for having invented the Diesel engine. At the time of this letter, Diesel was diligently working on altering and perfecting his 1893 engine design. This design would later be known as the diesel engine. The first prototype Motor 150/400, had been completed 12 July 1893. Initial tests proved it to be a successful concept. By October 1895, after the first prototype had been converted into the second prototype Motor 220/400, it had become clear that, a completely new engine had to be designed from scratch. On 20 February 1896, Krupp, Maschinenfabrik Augsburg, and Diesel, decided to start the development of the new engine. The new engine was supposed to be a 250 mm bore engine with a 400 mm stroke. On 5 March 1896, Diesel filed a patent application for supercharging; on 26 March, it was decided to build the new engine with a supercharger. In order to improve the efficiency of the development process, a new design bureau was built directly into Diesel's Augsburg testing laboratory. Several young engineers worked there, including Imanuel Lauster. On 30 April 1896, after Lauster had completed the drawings, the workshop at Augsburg began making parts for the engine. The first successful Diesel engine Motor 250/400, designed by Rudolf Diesel, was officially tested in 1897 by German industrial engineer Moritz Schröter. Schröter concluded, "we are beholding a quite marketable machine that has been thoroughly designed with great attention to every single detail." At this time, several firms bought licences for building legal copies of the Motor 250/400. It is now on display at the German Technical Museum in Munich. The recipient of the correspondent is Samuel Breslauer (1870-1942), a lawyer, journalist and editor, who rose to be head of the Politics department for the Berlin newspaper "Berliner Lokal Anzeiger", a daily newspaper with one of the highest national circulations of its time. Breslauer is remembered as one of the numerous Jews who were captured and deported camp during the holocaust. Surely his public role would have made him an immediate target by the German extremist leader. In August 1942, Breslauer and his wife Bertha were taken to the Theresienstadt concentration camp where they both died, she within four days.
