same principle. These inventions led to his being made, in 1846, a member of a commission in Berlin for the introduction of electric telegraphs instead of semaphores. He advocated the use of gutta-percha, then a new material, for the insulation of underground wires, and in 1847 designed a screw-press for coating the wires with the gum rendered plastic by heat. The following year he laid the first great underground telegraph line from Berlin to Frankfort-on-the-Main, and soon afterwards left the army to engage with Mr. Halske in the management of a telegraph factory which they had conjointly established in 1847. In 1852 William took an office in John Street, Adelphi, with a view to practise as a civil engineer. Eleven years later, Mr. Halske and William Siemens founded in London the house of Siemens, Halske & Co., which began with a small factory at Millbank, and developed in course of time into the well-known firm of Messrs. Siemens Brothers, and was recently transformed into a limited liability company.
In 1859 William Siemens became a naturalised Englishman, and from this time forward took an active part in the progress of English engineering and telegraphy. He devoted a great part of his time to electrical invention and research; and the number of telegraph apparatus of all sorts—telegraph cables, land lines, and their accessories—which have emanated from the Siemens Telegraph Works has been remarkable. The engineers of this firm have been pioneers of the electric telegraph in every quarter of the globe, both by land and sea. The most important aërial line erected by the firm was the Indo-European telegraph line, through Prussia, Russia, and Persia, to India. The North China cable, the Platino-Brazileira, and the Direct United States cable, were laid by the firm, the latter in 1874-5 So also was the French
