1866.| Wilde’s Magneto-electric Machine. 501 
to be very improbable, although it may be the case that the rays pro- 
ceeding from the electric light suffer so much more from absorption 
in passing through an obstructive medium than those from a flame 
produced by the consumption of oil, as to leave the oil light the 
more powerful of the two at great distances. If this were really so, 
it would follow that the application of the electric spark to light- 
house illumination is based upon a fallacy, The mere glare or 
splendour of effect to a near observer, so far from being an advan- 
tage to the mariner, is a positive evil, because, by its lustre, it tends 
to destroy his powers of perception of objects in the water that are 
nearer his view, and which therefore, from their proximity, threaten 
more immediate danger to the safety of his vessel. All the mariner 
requires is distinct visibility. The really useful power is that of 
penetration through an obstructing medium, and, therefore, the true 
measure of the usefulness of any light, is the distance to which it 
remains distinctly visible, and at which it preserves its character- 
istic appearance. This objection to the electric ight has only been 
made within the last year or so, and is apparently irreconcilable with 
the statements respecting its brilliant visibility at great distances, 
upon which so much stress was laid on its first introduction. 
Other difficulties have also been met with. The kind of know- 
ledge and attention required to render the magneto-electric light 
constant and sure is far above that necessary with the most elabo- 
rate oil lamp ; and the uncertainty to which the use of machinery 
of any kind is inherently liable, independently of the necessity of 
maintaining a constant supply of water, and the great difficulty 
of repairing and renewing the steam-engines and magneto-electric 
machines when required, all contrast most unfavourably with the 
certainty and simplicity attending the present oil lamp system. To 
this must be added the constant difficulty experienced in maintain- 
ing a class of persons for so responsible an office as that of engineer 
or attendant. A lighthouse, from its special nature, its great 
importance, its uninterrupted action, and its isolated position, is, in 
the language of Dr. Faraday, the last place to which processes com- 
paratively new in their nature should be applied, if there be any 
other educational positions which can precede such application. 
Now, in spite of all the care which the importance of the subject has 
rendered necessary, the Dungeness electric light entirely failed 
or was inefficient for upwards of 1194 hours, between August, 
1863, and October, 1864; and referrmg to this, the Hlder 
Brethren of the Trinity House say that it appears to them to be 
impossible to obtain entire immunity from such accidents, so long 
as human nature is subject to infirmity. These fallings off and 
cessations have frequently rendered it necessary that the ordinary 
oil lamps should be lighted, and notwithstanding the power of the 
magneto-electric light, instances have occurred of vessels being 
