The first Prussian telegraph lines used slow pointer telegraphs. Knowing how to make the conversion to Morse telegraphs allowed Charles Robinson to capitalize on the technology, which was not yet patented in Germany. In 1848 he sold 2 Morse telegraphs to the Berlin-Cologne line. He also took over the training of telegraphists. After a successful test operation, Robinson’s machine was used as a prototype for the remaining telegraphs for the Prussian lines, which were manufactured by Siemens & Halske.