LIGHTHOUSE ILLUMINATION BY MAGNETO-ELECTBICITY. 
69 
February, 18G2, this lamp was lit at Dungeness, but it was extinguished on account of 
the necessity of instructing fresh lighthouse keepers, who had to take charge of the ap¬ 
paratus, and it was not till the Gth of June that the brilliant star shone permanently on 
our southern coast. 
In the meantime, the French have not been indifferent or idle. When the Royal Com¬ 
mission visited Paris, the Lighthouse authorities were found experimenting with a com¬ 
paratively small machine, and had clearly not overcome the difficulty of maintaining the 
charcoal points at a proper distance. But they persevered, and last July there was pub¬ 
lished in the ‘ Moniteur Universel ’ a Report by M. Reynaud to the Minister of Com¬ 
merce and Public Works, in which he expressed a most favourable opinion of the Elec¬ 
tric Light, and the Minister gave an order for two Electro-magnetic machines to be placed 
in the double Lighthouse of the Cap de la Heve, near Havre. Thus France is following 
England in the adoption of this improvement in coast lights, just as, years ago, Great 
Britain followed France in the use of the Dioptric system of illumination. 
It is possible that some other nations may not fee behind the French. The Dutch 
Government contemplate placing an Electric Light at Scheveningen, and a second one at 
Texel. The Lighthouse system in the empire of Brazil is excellent, and they have long 
had an eye on the Electric Light. Sweden is on the alert; and inquiries also have been 
made respecting its management and cost by the Imperial Academy of Vienna. 
Apparatus .—Many readers will be familiar with the apparatus both of Mr. Holmes 
and of M. Berlioz, from having examined them at the International Exhibition last year. 
It would be very difficult to describe them without drawings, but the following may give 
a sufficiently good general idea. In the apparatus at Dungeness, the power that pro¬ 
duces the light is resident in 120 permanent magnets, of about 50 lbs. each, ranged on the 
periphery of two large wheels. This power is called into action by a steam-engine, with 
Cornish boilers, of about three-horse power, which causes a series of 160 soft iron cores 
surrounded by coils of wire to rotate past the magnets. The small streams of electri¬ 
city thus generated are collected together into one stream, and by a special piece of 
apparatus called a Commutator the alternate positive and negative currents are all 
brought into one direction. The whole power is then conveyed by a thick wire from the 
engine-house to the lighthouse tower, and up into the centre of the illuminating ap¬ 
paratus. • There it passes between two charcoal points, producing thus a most brilliant 
and continuous spark. The “ Lamp,” or “ Regulator,” is so contrived that by means of 
a balance arrangement and a magnet, round which the wire coils, the charcoal points are 
kept always at a proper distance apart. 
At sunset the machine is started, making about 100 revolutions per minute ; and the 
attendant has only to draw two bolts in the lamp when the power thus spun in the 
engine-room bursts into light of full intensity. It now requires little or no thought for 
three hours and a half, w r hen the charcoal points being consumed the lamp must be 
changed, and this is done without extinguishing the light, for it is the kindling of the 
second lamp that puts out the first. There are always several lamps ready at Dungeness 
in case of accident, and everything is kept in duplicate. 
The French machine is composed of 56 magnets distributed in 7 vertical equidistant 
planes, upon the angles of an octagonal prism. The maximum of intensity is obtained 
w r hen the machines turns 350 or 400 times per minutes, and the direction of the current 
is then reversed nearly 6000 per minute. There is no Commutator employed, and the 
alternate currents are not brought into one. 
Merits and Demerits .—In favour of the Electric apparatus, it maybe stated without 
any fear of contradiction that the light is vastly more intense than that produced from 
the most powerful oil-lamp, or any practicable number of argand burners. In truth that 
now shining at Dungeness is the most brilliant light in existence. The following state¬ 
ment will illustrate this. Professor Faraday says of it, when at the South Foreland, 
“ During the daytime I compared the intensity of the light with that of the sun, that is, 
it was placed before and by the side of the sun, and both looked at through dark glasses; 
its light was as bright as that of the sun, but the sun was not at its brightest.” No 
other light in existence would have stood that test. Again, he describes an experiment 
at Dungeness:—“ Arrangements were made on shore, by which observations could be 
made at sea about five miles off on the relative light of the Electric lamp, and the me¬ 
tallic reflectors with their argand oil-lamps—[the light formerly used]—for either could 
be shown alone, or both together. . . . The combined effect was a glorious light up to the 
