feet long. 71/2 beam, and 3 feet deep. The electromotor was invented by
Professor Jacobi; it virtually consisted of two disks, one of which was
stationary, and carried a number of electromagnets, while the other disk
was provided with pieces of iron serving as armatures to the pole pieces
of the electromagnets, which were attracted while the electric current
was alternately conveyed through the bobbins by means of a commutator,
producing continuous rotation.

We are not informed as to the length of time the batteries were enabled
to supply the motor with sufficient current, but we may infer from the
surface of the acting materials in the battery that the run was rather
short; the power of the motor was evidently very small, judging by the
limited speed obtained, but the originality of Jacobi deserves comment,
and for this, as well as for numerous other researches, his name will be
remembered at all times.

It may not be generally known that an electric launch was tried for
experimental purposes, on a lake at Pentlegaer, near Swansea. Mr. Robert
Hunt, in the discussion of his paper on electromagnetism before the
Institution of Civil Engineers in 1858, mentioned that he carried on an
extended series of experiments at Falmouth, and at the instigation of
Benkhausen, Russian Consul-General, he communicated with Jacobi upon the
subject. In the year 1848, at a meeting of the British Association at
Swansea, Mr. Hunt was applied to, by some gentlemen connected with the
copper trade of that part, to make some experiments on the electrical
propulsion of vessels; they stated, that although electricity might
cost thirty times as much as the power obtained from coal it would,
nevertheless, be sufficiently economical to induce its employment for
the auxiliary screw ships employed in the copper trade with South
America.