The Ohio Democrat. (Logan, O. [Ohio]) 1886-1906, 1893-12-16
THE LARGEST LIGHTHOUSE.
On Clear Night the Light is Visible One
Hundred and Thirty Miles.

On n clear Night the Light ~ visible One
Hundred and Thirty Miles,
If there is one thing the French gov
ernment has endeavored to do we'll it
has been to warn mariners of danger
Gus parts on the French coast, and If
there is n spot where the Service des
Phares de France has largely expert
mented with view to providing the
best method of lighthouse illumination
it has been at the lighthouse at the
Cap de la Heve, near Havre. Four diff
ferent kinds of apparatus have al
ready been tested at this lighthouse
The first comprised oil lamps with re-
Electors, giving n luminous intensity of
eight thousand candle power, visible
in clear weather distance of forty-one
miles. In the second case oil lamps
were used with fixed lenticular appa-
ratus. yielding a candle power of nine.
teen thousand, capable of being seen
in clear weather distance of forty.
nine and one-half miles. The third
comprised the employment of the elec-
trio arc light, with fixed lentcular ap-
paratus, giving an illumination of
twenty-four thousand candle pow II,
the light being visible tifty-scven
miles away. In the fourth case the
use of the electric arc light was COM
bined with a lenticular flashing appa.
ratus, yielding twenty-four million
candle power, and capable of being
seen on clear night no less than one
hundred and thirty miles distant.
A new light has, however, now been
practically completed at this light
house and this will give a luminou.
intensity of 40, 900, 600 candle power ant
it will be the most powerful lighthous,
light in the world. AS far as the elec
trical apparatus is concerned, the ole
magnetic machines have been dispensed
with and four new generating ma
chimes have been substituted. These
are two continuous-current dynamos,
giving each from twenty-five to 100 am
peres at a pressure of seventy volts,
and two new De Meritens alternat ting
current magnetic machines, yielding
from twenty-five to 100 amperes at an
electro-motive force of from forty to
forty-fve volts The current yielded
by these machines will be utilized for
producing light in Serrin regulating
lamps fitted with cylindrical carbons
The optical apparatus which has re-
placed the old fixed lights is of new
| type, devised by M. Bourdelles, one OF
| the chief engineers of the Service dcs
Phares, and who was prominent
member at the recent international
maritime congress held in London.
This apparatus gives white flashes
which succeed each other every five
seconds, and it possesses this peculiar
ity-that the number of lenticulal
panels, which in lighthouses of the frs
order ranges from eight to sixteen, ha.
been reduced to four. The difficult,
of revolving the panels at the necessary
rapidity to produce the flashes at suffi
GENTLY regular intervals has hitherto
prevented the realization of this i'm
portant Improvement; but this has nov
been overcome in an ingenious manner
and it is now possible to make a com
plete revolution in twenty seconds, a
compared with minimum of four min
utes with the ordinary lights of tn
first order. The square lantern ha
been demolished and circular on
, substituted. The new light will, a
, already mentioned, be the largest light
house light in the world. During eleve
months of the year the light at tn
Cap de la Heve will be visible from it
) geographical bearing distance G
twenty-three miles, while with the oil
fixed lights this limit has only bee
obtained for eight months in the yeal
leaving out of consideration the create
luminous intensity obtained with tn
new apparatus.-Pal Mall Gazette.