Speaking of condensers, he said he had
recently tried lead plates in water to get large capacities, but so
far had not been successful.
Mr. Swinburne, in replying, said he had not made a perfect condenser
yet, for, although he had some which did not heat much, they made a
great noise. He did not see how the rise of pressure observed by Mr.
Ferranti and Mr. Kapp could be due to resonance. Mr. Kapp's experiment
was not conclusive, for the length of spark is not an accurate measure
of electromotive force. As regards Mr. Mordey's observation, he
thought the action explicable on the theory of the leading condenser
current acting on the field magnets. The same explanation is also
applicable to the Deptford case, for when the dynamo is direct on, the
condenser current is about 10 amperes, and this exerts only a small
influence on the strongly magnetized magnets. When transformers are
used, the field magnets are weak, while the condenser current rises
to 40 amperes. Mr. Blakesley's method of determining losses was, he
said, inapplicable except where the currents were sine functions of
the time; and consequently could not be used to determine loss due to
hysteresis in iron, or in a transparent dielectric.--_Nature._
* * * * *
THE TELEGRAPHIC COMMUNICATION BETWEEN GREAT BRITAIN, EUROPE, AMERICA,
AND THE EAST.
By GEORGE WALTER NIVEN.
There are at present twenty-six submarine cable companies, the
combined capital of which is about forty million pounds sterling.
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