ed an officer's
commission.

Physics and chemistry were his favourite studies; and his original
researches in electro-gilding resulted in a Prussian patent in 1841.
The following year he, in conjunction with his brother William, took out
another patent for a differential regulator. In 1844 he was appointed
to a post in the artillery workshops in Berlin, where he learned
telegraphy, and in 1845 patented a dial and printing telegraph, which is
still in use in Germany.

In 1846, he was made a member of a commission organised in Berlin to
introduce electric telegraphs in place of the optical ones hitherto
employed in Prussia, and he succeeded in getting the commission to
adopt underground telegraph lines. For the insulation of the wires he
recommended gutta-percha, which was then becoming known as an insulator.
In the following year he constructed a machine for covering copper
wire with the melted gum by means of pressure; and this machine is
substantially the same as that now used for the purpose in cable
factories.

In 1848, when the war broke out with Denmark, he was sent to Kiel where,
together with his brother-in-law, Professor C. Himly, he laid the first
submarine mines, fired by electricity and thus protected the town of
Kiel from the advance of the enemies' fleet.

Of late years the German Government has laid a great network of
underground lines between the various towns and fortresses of the
empire; preferring them to overhead lines as being less liable to
interruption from mischief, accident, hostile soldiers, or stress of
weather. The first of such lines was, however, laid as long ago as
1848, by Werner Siemens, who, in the autumn of that year, deposited a
subterranean cable between Berlin and Frankfort-on-the-Main. Next year a
second cable was laid from the Capital to Cologne, Aix-la-Chapelle, and
Verviers.

In 1847 the subject of our memoir had, along with Mr. Halske, founded
a telegraph factory, and he now left the army to give himself up to
scientific work and the development of his business. This factory
prospered well, and is still the chief continental works of the kind.
The new departure made by Werner Siemens was fortunate for electrical
science; and from then till now a number of remarkable inventions have
proceeded from his laboratory.

The following are the more notable advances made:--In October 1845, a
machine for the measurement of small intervals of time, and the speed of
electricity by m