The daily morning Astorian. [volume] (Astoria, Oregon) 1883-1899, 1894-11-21
OF INTEREST TO MARINERS.
An Answer to Captain Merry's Letter
on Coastwise Navigation.

An Answer to Captain Merry's Letter
on Coastwlse Navigation.
In recent issue of the San Francisco
Commercial News, Capt. Merry had a
very interesting letter relating to
coastwise navigation. 1t was reprinted
In last Saturdays issue Of the Asto-
rlan. The following is an answer to
the letter from the pen of Captain d.
Buchanan, and is copied from the same
publication:
Permit me through the aid of your
valuable paper to supplement with a
few facts Captain Merry's letter in your
issue of November 18th on the naviga-
ton of coastwlse steamships. / quite
agree with Captain Merry that the
patent log is valuable aid to navlga-
tion, where the shlpmaster carefully
registers the percentage it goes (slow
or fasD by well authenticated observa-
tlons. The use Of the log is also inval-
liable when approaching the land in
1 dark night or In thick weather. but
one or two casts of the lead are COM
paratlvely useless. 1t requires a series
Of soundings taken at stated intervals,
where the speed of the ship is known,
and each cast should be recorded on a
cardboard, whereby continuous line
Of soundings Is formed This placed on
the chart at or near the ships sup
posed position will either verify the
ships position on the course steered,
or 1t will show conclusiHely the ships
position at the first and last soundlngs,
and the distance run in the interval.
Captain Merry says that steamship
running on parallel course with an
adjacent coast line will ultimately run
on shore" This is evidently a stretch
OF the imagination, as gravity is a force
that draws toward the center and not
towards the shore; If due allowance in
the course steered is not made for an
lnshore current or heavy swell sweep
Ing towards the land, II Is evident the
ship Will ultimately be stranded. Now,
as to the local magnetic disturbance
Of the compass on board ships when
near the land-the reports which have
been current for many years past. of
he disturbance of the compass on
board ships when near land, have gem
srally been regarded, until OF quite re-
'ent years, as very doubtful, II not
yold OF foundation. 1t has rightly been
objected that allowing the nelghboring
and TO te entirely composed of mag
letic ore, the distance at which the
disturbance OF the compass
ook place was quite enough TO render
Is attraction or repulsion without ef-
ect. There are some parts OF the
World where the bottom of the ocean,
3 sufficiently magnetic and close
'nough TO effect the compasses. The
mariner has therefore. reason for IN
'reased vigilance when nearing the !
and of certain countries during thick |
weather. Instead Of attrlbuting the
oss OF vessels when approaching a |
'oast to the magnetic effects OF fog and |
and and other improbable influences
lpon the compass. II would be much |
more reasonable to ascrlhe It TO the
conditions Of her magnetism |
" induction during the passage, and
which has not been discovered or kept |
recount Of by frequent Azimuths pre-
'ious TO closing in with the land. A !
curse Is shaped which the captain
links perfectly safe; 10 his astonish'
nent Il lands his vessel on some rock
r shoal and the fault Is laid on the
ompasses whereas they have only
heyed the magnetic forces which have
hanged the oompasses during the
ong voyage, The longer ship steers
n a given course or lies in the same
eneral direction. the greater win be
he magnetic charge OF induced mag
etism and the more slowly WIN Il
move and shift with the changing
curses Of the vessel The other mag
etic qualities Of ship are compara-
lively stable. but the induces magnet
nm Is treacherous and changeahlo and
eouires constant vigilance to prevent
lsaster The heeling error Is another
ource Of danger when not carefully al
,wed for. and. as It Is at It's maximum
a north and south courses .the coors-