Weekly expositor. (Brockway Centre, Mich.) 1882-1894, 1889-08-15
LIGHTS FOR MARINERS.
Electricity Rapidly Supplanting
All Kinds OF Mineral Oils.

All Kinds of Mineral Oils.
The last century has seen very
considerable increase in the numb er
of lighthouses and light-vessels on
the various coasts OF the world. Con-
sequently, with the enormous increase
in the number of coast lights very
great improvements have from time to
time been effected in their efficiency,
says the New York Times. Ancient
lighthouses were erected on proml-
nent parts of the cost beyond actual
attack by the sea, and in many in
stances they were at considerable dis
tances from navigable waters; and so
with their pickering and feeble wood
and coal fires they were far from eff
cient as aids To mariners. So slowly
was lighthouse illumination develop
ed that the last coal-tire beacon on the
coast of England was not replaced by
oil until 1922.
Modern engineering efforts, how
ever, in directing the great sources OF
power in nature for the convenience
of mankind, may be said to have be-
gun about two hundred years ago with
lowed up, have been so successful in
conversing hidden dangers into
sources of safety, thereby, assuring the
safe guidance OF the hardy toilers of
the sea. In 1859 the Eddystone light
house was illuminated by twenty-four
candles weighing two-tifths Of n pound
each. No optical apparatus, however,
was used for condensing their radiant
light and directing it to the surface of
the sea. At the current price of tallow
candles the cost per hour in those
days vas sufficient TO provide a min
eral oil light at the focus OF modern
optical apparatus which would pro-
duce "a beam of about twenty -four hun
dred times the intensity.
In the invention OF the cylindrical
wick lamp by Argand a much more eff
fcient focal luminary was provided
than the fiat wick lamp previously en-
ployed, and il was very soon generally
adopted for both fixed and revolving
lamps. Another very important in
vention, also by Frenchman, was
that of the dioptric system of Fresnel
and the addition of second, third
and fourth concentric wick. The slow
progress made with coal gas abrord
was chiefly due so the great cost in
Cured in obtaining the proper quality
of the refined article. Cola, or cab
bage seed oil, was the kind most gen
orally used. Experiments we're also
made by throwing oxygen TO the mid
die of flame derived from the COM
bustion of fatty oils, which gave an
increased intensity over that of the
flame of the largo oil burner not suf-
ticient, however, to justify the greatly
increased cost.
In 1857 there were some expert
ments made in England with direct
current magneto-electric machines for
the production of the arc |, rht, which
gave such promising results that a
practical trial was made in one of the
English lighthouses, happy exam
pie OF the steel magnets being made,
not only TO guide the mariner on his
course, as in the case of the compass,
but also TO warn him of danger. The
irregularities OF the current not being
sufficiently under control in those early
days of electrical machinery, a con-
slant substitution of oil was necessary,
and as no advantage of brilliancy can
counterbalance the want OF certainty
in signals for the guidance OF the nav
igutor, no further steps were taken at
that time to develop the electric light
in England. But in France it met
with more encouragement, and there
W. s established at Cape La Heve a
system of electric illumination that
seems to have been very much more of
a success than was the case across the
charnel.
In 1877 the Lizard lighthouses on
the south coast of Cornwall were
lighted by electricity, many OF the
former serious difficulties have been
overcome. In the meantime the sue
cessful development OF the electric arc
light acted as a keen stimulous TO in
ventors OF burners for producing oil
luminaries for lighthouse illumination.
Gas and the Drummond or lime light
were both eXperlrlented with and at
tention was directed to the question of
substituting mineral oil for COLA; but.
owing 10 the imperfectly-re
mineral oil and its high price, the re-
suits at that time were not found to be
so satisfactory as to justify change
from the vegetable oil.
The time, however, was at hand when
it was absolutely necessary that an ex-
haustive series of experimental trials
should be made on practical scale for
the exact determination of the relative
efficiency and economy of electricity,
gas and mineral oil as lighthouse
illuminants. The South Foreland
station, England. was selected on ac-
count OF the existing facilities for OBJ
servations on land and sea, and the ex-
periments were from time 10 time wit
messed by representatives Of almost
every country. A period Of twelve
months was devoted TO the tests, which
were watched by numerous observers,
trained and unframed, scientific and
practical. The general results Of the
photometric measurements of the three
illuminants demonstrated that the oil
and gas lights, when shown through
similar lenses, were equally affected by
atmospheric variation, that the electric
light was absorbed more largely by
haze and fog than either the oil or the
gas light, and that all three were near
ly equally affected by rain. The con-
clusion arrived at was that for ordinary