The Bottineau courant., 1912-12-27
THE uNERR|NC sun
Il Is Uncle San,'s Most Reliable
Lighthouse Keeper.
NEVER FALTERS IN ITS WORK.
Dy tho Aid Of tho Wonderful Sun valve
Il Lights the Acetyisns 6sacons 40 It
Sets At Might and Extinguishes Thorn
a. II Rises In the Morning.

It Lights the Acetyisns Bsseons AZ It
Sets at Night and Extinsuishss Thorn
a. It Rises In the Morning.
The sun is the most trustworthy OF
light house Keepers. The sun or the
heat from it lights many hundreds OF
beacOnS along our coasts and water
ways evening after evening and ex-
tinguiShes them punctnally every morn
ing. They are guides on land and sea
that are never touched by human hands
from one months end to another The
way in which the United States gov
ernment. through it's lighthouse board.
has utilized the services of the sun and
made that great lamp Of heaven a
faithful and unerring servant is most
interesting
The discovery Of acetylene gas was
the first step toward retiring the lonely
keepers Of the little lights in farotf
places. Modern magic was not slow
in recognizing the fact that by the ap-
plicatiOn of certain well known scien-
t1flc principles the lighting Of the great
chains Of beacons that girdle the COASTS
of the two seas and the gulf and cover
the great lakes and every navigable
strea m in our huge country could be
much simplified
The United States did not become in
terested in the acetylene light and it's
automatically generating gas buoy until
about the year 1906 and did not adopt
it until 1908. Then the engineers of
the lighthouse board devised some
wonderful improvements, among them
the utilization of the sun.
The self lighting and self extinguish-
ing acetylene beacon is a very simple
thing but it depends almost entirely
on the ''sun valve." which is one Of the
most wonderful but least complex of
the achievements of modern science.
In the first place. the source of light
for these lone beacOns is dissolved
acetylene. which is stored under pres
sure in steel cylinders. One of these
cylinders can he charged with enough
gas to last small beacon three years.
Usually. however. in the case of hOat.
ing buoyS. six months supply is all
that is necessary. as such buoys are
overha ulcd and painted twice a year.
Knowing the size of the fame and it's
hourly consumption Of gas. it is very
easy to compute how long cylinderful
will last and how often it will need to
be visited. That is all the care the
light will need. The sun valve does
the rest. r.
The scientific principle upon which
the sun valve depends is that light
waves become transformed in different
degrees. according to the nature of the
intercepting body. Sunlight upon dark
surfaces is converted into heat, and
heat produces expansion. This expan-
sion is especially perceptible in certain
metals.
In carefully sealed and substantial
~ mounted glass jar nearly foot
high and about one-fourth that in d.
ameter a thick black rod is placed per-
pendicularly through the center. It is
supported by three slenderer rods of
highly polished copper. The big black
rod is of copper also and is coated with
lampblack to make it absorb light to
the greatest possible degree. The sup
porting rods reflect light without alb
sorbing it and do not expand or con-
tract to the same extent as the largest
rod.
The thick black piece of copper in
the center of the jar is extremely SEN
sitive to light and heat. As the sun
appears and the atmosphere grows
warmer in the morning this rod length
ems. 1t pushes down into the metal
chamber in which the glass jar rests
and touches the end Of 4 lever. 1t
presses down on this lever. which is
controlled by spring and cuts of the
dow of the gas to the lamp.
When the sun disappears from view
in the evening and the temperature of
the air falls the process II reversed.
The rod contracts and releases it's pres
sure on the lever. allowing the gas to
dow upward to the lamp The gas is
ignited by a little pilot fame that is
never extinguished. Thus the beacon
is lighted at the proper time and is put
out when it is no longer needed. al
though along desolate coasts it may
never gladden. the human eye for
| months at time.
The engineers Of the lighthouse board
say that the precision of this device is
almost incredible. 1t can be used with
equal certainty in equatorial heat and
in polar cold. for it responds with the
| utmost accuracy to small variations in
! temperature. 1t is used on lonely is
| lands in the Pacific. There are nearly
| a hundred of these sun valve beacOns
| in Alaska. In summer they are aids
to navigation. and in winter they guide
| the travellers on dog sledges over the
frozen wastes.- Harper's Weekly
,... Deadly.