ompany, of Wilde, and of Gramme,
constitute a brilliant fulfilment of this prediction.

But, as regards the augmentation of power, the greatest step hitherto
made was independently taken a few years ago by Dr. Werner Siemens and
Sir Charles Wheatstone. Through the application of their discovery a
machine endowed with an infinitesimal charge of magnetism may, by a
process of accumulation at compound interest, be caused so to enrich
itself magnetically as to cast by its performance all the older
machines into the shade. The light now before you is that of a small
machine placed downstairs, and worked there by a minute steam-engine.
It is a light of about 1000 candles; and for it, and for the
steam-engine that 'works it, our members are indebted to the
liberality of Dr. William Siemens, who in the most generous manner has
presented the machine to this Institution. After an exhaustive trial
at the South Foreland, machines on the principle of Siemens, but of
far greater power than this one, have been recently chosen by the
Elder Brethren of the Trinity House for the two light-houses at the
Lizard Point.

Our most intense lights, including the six-wick lamp, the Wigham
gas-light, and the electric light, being intended to aid the mariner
in heavy weather, may be regarded, in a certain sense, as fog-signals.
But fog, when thick, is intractable to light. The sun cannot
penetrate it, much less any terrestrial source of illumination. Hence
the necessity of employing sound-signals in dense fogs. Bells, gongs,
horns, whistles, guns, and syrens have been used for this purpose; but
it is mainly, if not wholly, with explosive signals that we have now
to deal. The gun has been employed with useful effect at the North
Stack, near Holyhead, on the Kish Bank near Dublin, at Lundy Island,
and at other points on our coasts. During the long, laborious, and I
venture to think memorable series of observations conducted under the
auspices of the Elder Brethren of the Trinity House at the South
Foreland in 1872 and 1873, it was proved that a short 5.5-inch
howitzer, firing 3 lbs. of powder, yielded a louder report than a long
18-pounder firing the same charge. Here was a hint to be acted on by
the Elder Brethren. The effectiveness of the sound depended on the
shape of the gun, and as it could not be assumed that in the howitzer
we had hit accidentally upon the best possible shape, arrangements
were made with the War Office for the con