Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1909-02-19
OUR COAST Goa |! !. lB||lE!|' J {
Cheering Lights That Warn and
- -. u Guide the Mariner. ." -.

cheering Lights mat warn ana
=, ~ y Guide the Mariner. -
M. yIz3 4 - = - : - =, lssssl
A BLAZE Of KEROSENE. I':'I EN- OIL.
The Wonderful Lamps and Lenses
That Produce the Brilliant and Far
reaching Flams-Why Electricity Is
, Not Used In Lighthouses.
~ The goal toward which the light
house board Of this country u striving
is a continuous chain OF lights com-
pletely encircling the United States
and possessions and IN the case Of riv-
ers and inland seas bounding the wa
tiers on all sides, so that II ship may
never. leave the area Of q light thrown
by one lighthouse before entering the
circle Of the light Of another. AS fast
as congress, will appropriate the money
the gaps are being filled. =,
But what makes the light2 When
the curious inquirer is told kerosene"
he naturally wonders why his own
student lamp does not give a. better
light If the same oil in the, lighthouse
sends its beam from five to twenty five
miles.
Various methods of lighting were in
use until 1910, when a new system
was introduced Of employing nearly
true paraboioid reflectors and better
glass lenses. In some cases these re-
Electors gave light which Is not sur
passed even today. except when han
died with Intelligent care In 1852,
when the present lighthouse board was
Instituted, the Fresnal system Of len
ticular glasses was introduced from
France and still remains. The first
cost is great, but by theSsaving Of oil
over the reflector system this is soon
reduced. With any reasonable care
fine light always results, and it is i'm
possible for a keeper to maintain a
poor light with this apparatus without
fragrant disobedience OF instructions.
Even with such an apparatus no
common. lamp can supply the light.
First order lamps have Ave wicks, one
inside the other, and are fed with oil
by pump and pipe system. The oil
is fed to the wicks SO that It reaches
the ends where the fame IL in the
right time and in the right quantity.
1t is difficult to look at It, 30 intense
is the light. In the lenses rather than
In the lamp is the secret, for they pick
up and utilize nearly all the rays o.
light which ordinarily 60 astray. The
Fresnel apparatus collects almost all
Of this waste light and reflects and
refracts it out in one great broad
beam Of light, parallel to the surface
Of the sea, where 1t Is needed.
The flames which come from the
lamps are largely transparent. So, Of
course, are all other similar flames. If
flames were not transparent there
could be no advantage in having one
lame inside another and q third inside
the frst two, etc The IL Ats from
the inner flames could not get out and
would do no good. Y
In some lighthouses, usually for
range light purposes, the light 70 all
to be concentrated In one beam. This
Is done by concentric rings of prisms
and a central bullseye and reflector.
Vessels getting such q light inrange,
either by itself or with another Hight
and running down the beam, areSsafei
from obstructions which may be near
by, the range lights or beams Of light
marking out the channel to eSfoi--::
lowed. Il M ,ss
II Ii frequently asked Of light keep
ers Why lectricity n not-~used in
place Of mineral OH. An electric light
IL expensive to install and difficult and
expensive 30 maintain. There n al
ways difficulty in keeping the arc ex-
actly in the focal point of the lenses,
the carbons never burning twice alike
and constant watching being neces-
sary. Failure to have the light source
exactly In the focal point Of the lens
results in sending the light raysupsor
down instead Of straight out, where
they are wanted. Electricity, while
superior In penetrative power In q
fog, has no advantage over a power
full oil lantern in clear weather. Min
eral oil. cola oil or lard oil lights Of
the first order could be seen 4 hum
dred miles were 1t not for the curya-
ture Of the earth, and al long ~ the
light is visible long before the coast
Is all purposes are served.
It is only within recent years that
mineral oil has been In use. Lard oil
succeeded COLA oil and was used ex-
clusively up to 1880 and with mineral
oil up to 1850. Since the latter year.
mineral oil has been used entirely, ex-
cept where electricity has been expert
mented with, or coal or acetylene gas.
So far coal oil, for power efficiency,
cleanliness, ease, of operation and
.cheapness, holds its own against III
other means Of tight making
! Electricity, II II can be succesjfully
installed, is the best light, but through
expense Of maintenance and in the In
ability to get skilled attendants for
such light for the price set on keep