The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1900-03-08
NAVIGATION ON THE SEA.
HOW SHIPS FIND THEIR WAY
ACROSS THE TRacNLEss OCEAN.
The Captain and Hts sextaut-John
Harrison and the Important l"-
vention of the Chronometer-N
Great Man Hut Little known.

Any ono who has ever been passenger
on great transatlatic liner OF to-day
knows what an important, imposing per-
sonage is the brass-bound skipper n
very different creature Is he on the deck
Of his ship from the modest ssafArinG
man we meet on land. clad for the time
being in his shcre-geing toys, hut the
captains dignity IS not all brass buttons
and gold braid lie has behind him the
powerful support Of a deep. delightful
mystery. lie It Is who takes the sun
at noon. and finds out the ships path at
sea. And In truth. regarded merely as
a scientific experiment the guiding OF
vessel across the unmarked, traeklesS
ocean has few equals within the whole
range OF human knowledge II IL the pur-
pose of this brief article 20 explain the
manner In which this seeming itnpossi-
hiiity is accomplished We shall not be
able 10 so sufficiently into details TO en-
able him who reads TO run and navigate
a magnificent steamer But we hope TO
diminish somewhat that part OF the cap
tain's vast dignity which depends upon
his mysterious operations with the SEX
tant.
To begin, then, with the sextant Itself.
II Is nothing hut an Instrument with
which we can measure how high up the
sun is In the sky. Now, every one knows
that the sun SLOWLY climbs the sky In the
morning. reaches It's SrtAfsSt fieiRnN al
noon. and then slowly sinks again I'm the
afternoon. The captain simply begins 20
watch the sun through the sextant short
" before noon. and keeps at II untii he
discovers that the sun IL Just beginning
to descend, That Is the instant of noon
on the ship. The captain quickly chances
az the chronometer. or calls out moon
| 20 an officer who Is near that instrument.
| And the error OF the chronomcter be-
comes known then and there without
any further astronomical calculations
whatever
Incidentally. the captain also notes with
the sextant how high the sun was tn the
| sky at noon. He has I'm his mysterious
| chart room" some printed astronomical
tables. which tell him In what terrestrial
latitude the sun VIII have precisely that
height on that particular day OF the year.
| Thus the terrestrial latitude becomes
known easily enough, and II only the cap
| tain could get his longitude too h. would
| know just whore his ship was that day Mt
noon
We have seen that the sextsnt observa-
tions furnish the error az the chronomc-
| ter according 20 ships time at noon. In
| other words, the captain Is In possession
/ OF the correct local time I'm the place
/ where the ship actually IL. Now, N he
| also had the correct time at that moment
| OF some well-known place ON shore no
| would know the difference In time between
| that place on shore and the ship. hut
/ every traveller by land or sea n aware
that there are always differences of time
| between different places on the earth. IL
watch he right on leaving New York.
for Instance. a Will hA. much ton fast an
| arriving nj Chicago nr san Frnnctsco.
| the farther you 10 the inrrer becomes the
| error OF your watch. In fact. II Won could
| find cut how much your watch had gone
into error YOU would in a sense know
how far east and west you had travelled
Now, the captains chronometer III set
| 90 correct Greenwich time" on ahors
| before tho ship leaves port His ooserva-
| lions having then told him how much this
| is wrong ON that particular day. and In
! that particular spot where the ship II. he
knows at once just how Gar he has trav-
| eIod east west from Greenwich. In other
| words he knows hts Longitude from
Greenwich" for longitude ~ nothing more
| than distance from Greenwich in an east
and west direction. just aA latitude fl only
| distance from the equator measured in a
| north and south direction. Greenwich
| observatory Is selected aH the beginning
OF things for measuring longftmdes. be-
| cause that worthy monarch Charles ~.
twho seems "a have done enc wimp thing,
established II al date preceding tho
foundation % all other existing aaironorn-
icai ohservatofio~.
one o. the mast interesting hits ~ as
Economical history enacted On con-
necfion with this matter ~ longitude.
From what has been said. Il IL clear that
the ships longitude will be obtained COR
reetiy only II tho ehronnmcfcr has kept
exact time since the departure ~ the ship
from port Even y very small error OF tho
chronometor wlll throw ont tn. ionxftuda
coed many mlieR and We can Under.
stand readily that II must 10 difficuit IN
the extreme 90 construct n mechanical
contriyanee capable ~ keeping exact time
when subjected 20 the rolling and pitching
81 vessel sf sea
u was ~ r~renfiy A. she year ssN taat
the first Instrument capable ~ keegian aiiy.
thing hkw accurate time AZ sea was Esc-
cesAfeilg compiessd. u Nas the work 81 al
Enaiisa MATCHMAKER named john Harrison
and u one ~ tas few great improvements
IN matters scientific which fas world owes
10 desire ~ winning a money Prize u
appears that IN i7is committee was ap-
pointed ~ th~ house. - commons aita no
iess person than ST. isaac Newton aiaastif
a. one ~ is members. ~ consider shs o.
STABILITY ~ Offering governmental anesAsr.
nEemnri fGr ire Invention 81 satpe means ~
finding the lsFsxiisds 90 sea Finally -
Hg1tish government offered = reward -
Fa8s Tor an irstyfHn@nt wHseh M0mga anf
the iongsiuas sHhin sixty nsles. " 40 II
wiihla forty rniiea, ard SleNo, n aishis
Thirty miles Hanim9Ws farpnauaatMr was
finished W TBS, has be aid Hpf rere3Ee ina
final payment Il HE pfiEo Until tTs4
We have net srsze - enter into an -.
procedures 20 shica 40 &aa forced Is subj
uIi' suriag those tWeffy eight innx years.
y is matter ~ satisfaction that Harm son
lived - receive The money Mhioh h. nad -
thoroughly sssfpsd 10 Rad fho ReHius ~
plan and rsaHtef INTRICATE fnffhas8-sI De-
tails. bgi perAapa ha Iarssd 81 F0nas degrees
ire a3asfy - tonxge sna ren 20 hiring thefa
hnms 80 others Tl4la may - ne FeaA8n
he Is - little sn9Rn. fhgsxa 81 was ais
fortune 90 canyibste ~ Afga cad es@Hilag
o psft 20 thn gerfee'iau ~ modern nAvtxA.
ttun Let ns hoge tais brief mention may
serve 10 recall h-a memory from ehilgion
even for a fseunE f3Qfnanf. fhag Na may
not have written N vain ~ fAAt ioukltuds
70 which ms nfs vau Efvefl New Yorx
Evening Pest.
RED Raven seiita Club aaala mith Mon.
ogT2m whisky. a. HagEertF'p to Second
avenue south
peYFfsrAggFs so~ 9afs~sfss. .fe-ks 90