The Bemidji daily pioneer., 1918-02-22
United States Swept Bare Of In
n struments Used to Guide
Ships.
Old CAPTAINS Ii RESCUE /.


fectS Of the war was an aente short
age Of the instrument most used in
navigating ships Az sea the sextant.
/ n few weeks after the United
States became IA party to the great
struggle, the market was swept bare
Of what might be termed the doating
supply Of these important Instruments.
Since then, importat IONS from Eng
land, Canada and France have eased
the American market somewhat. but
there Is still q sufficient shortage to
hold the price far above what It for
nierly was. U
In the early months of this coun-
tfy's participation Ii the. Nar, when
tie United States shippinS board was
} establishing the chain Of nayigation
/ schools at which It 70 taining 0hi-
Hc{rs for the new merchant marine,
there was such q scarcity of these:
Necessary Instruments htch are
uSed daily in the schools to teach
methods Of determining ships posi-
Etion at sea that III appeal Was made
Tor the loan 81 inst truments.
The result was striking. Out: Of the
closets and attIs Of former captains
homes, particularly IN New England,
sextants appeared that had not seen
the light, In some cases, since the days
OF the clipper-ship era, when the Unit
ed States was supreme on the sea.
Many Of these instruments had been
on long voyages to the mysterious.
East; others had been in the whale
fishery to the far North; q few had
been s carried among the CannibaI
islands Of the South Pacific, others
among the pirates of the China seas.
It had not been though when these;
instruments were slowed away by
careful hands, years ago, that they
would ever again serve the merchant.
marine. Today many Of them are be-
ing used by. young men who will quail
ify as officers on the new and greater,
merchant marine, while others, which
have been presented to the shipping
board, are actually making voyages
again, this time among the pirates Of
the submarine zone. II. ssa8
"A. sextant. unlike a watch or any
instrument with constantly moving
parts, Is very slow to wear out. There
is not much difference In the sextant
Of today and the original sextants pro.
duced in England when the instru-
ment was first perfected By John
Hadley, back IN 1871. \.
q First Was m octant.
Hadley called his instrument at first
an octant;. because It represented In
Its scale OF degrees but an eighth part
OF the circle, that is, 45 degrees. Later
instruments were termed quadrants,
as they represented a quarter Of q cir
Gle, 80 degrees. The sextant, or sixth.
of circle, go degrees, was found to.
be most practical, and in time came
into general use. The practical dis
8tinction between these three instru-
ments Is slight, however.
The first sextant was not an inven-
tion, as might be supposed, but an
adaptation of ancient instruments
used by astronomers from time imme-
mortal to determine the suns eleva-
tion, or latitude. The oldest Of. these
ancient instruments was the astrolabe.
a disk Of copper or brass, cut to the
full circle Of $50 degrees. This was
fitted with plumb line, and on Its
face bar pivoted on the center, and
having at one end pin. One man
held up the disk by the line, another
sighted the sun over the pin In the end
OF the bar, and another noted where
the shadow cast by the pin fell on
the scale Of degrees marked on the
disk.
It thus took three men to make an
observation, which was usually faulty,
while the use Of such an instrument
on moving ship was almost an Inn
possibility.
Another ancient observing instru-
ment was the cross-staff. This consist
ed Of a bar of wood some OF them
were seven feet long fitted with q
sliding upright bar, or cross. The
long bar was held toward the sun, and
the observer was posted at one end.
The shorter bar was then moved back
or forth until the observer saw the
sun over its upper tip and the hori-
,, izon at the same time under its lower
tip. The angle thus determined was
marked on a scale on the long bar.
4 A grave objection to this instru-
ment was that the observer was
obliged to look at the sun and the
horizon at the same time.
Columbus used both instruments on
his voyage to the new world, but ap-
parently neither helped him much In
determining the position Of his ships,
which he could only guess at until he
made a landfall In the West Indies.
Hadley Invents instrument
John Hadley conceived the idea OF
employing the principle Of the cross
star In an instrument that would en-
able the observer to see both the
sun and the horizon when looking at
the latter. This he accomplished by
arranging a series Of mirrors In such
way that the observer by the move
ment Of an arm. or lever. attached to