Rock Island Argus., 1920-01-08
Frederic Haskin's Letter


/ merchant ships. It not only helps
q ship to enter q harbor, but It en-
ables . ship within 60 miles Of a
coast to determine its position even
when the stars are not visible.
When you understand that nearly
all wrecks are caused by ships
running ashore in the fog. through
ignorance Of position, you appre-
ciate the value of this method to
vessels travelling near the coast. It
means that the toll Of life and
property taken by dangerous capes
like Hatteras is greatly reduced
But this method did nothing for
the mariner far at sea. He could
pick up the wireless message from
the shore stations, but he could not
send messages in return, because
the puny wireless on board q ship
is only reliable for distances less
than hundred miles. It is hard
to explain this matter to layman
especially for another layman)
but suffice 1t to say that in order
to compute his position by trigo-
nometery, the computer must have
at least one known distance. That
is where the shore station comes
in. The shore station knows its
own position, and the distance to
some other point, say another
shore station. 1t can get the direc-
tion Of the ship. The computer on
shore can then draw two lines of a
triangle. By trigonometry he can
compute the third line, and COM
plete the triangle. The position OF
the ship is the apex of the triangle.
Whether this Is clear to you or
not, you will understand that the
mariner in mid-ocean lacks the
two positions. He could find out,
with his little direction finder, in
what direction some shore station
lay. for his wireless could always
pick up messages from shore sta
tions. He could locate that shore
station on the map. He then had
one point and one direction. He
could draw one line of his triangle
and that is all. He could say with
certainty, for example. that the
station at Old Point Comfort was
due west Of him, but he could not
tell how far west.
The contribution of Clements
consisted in pointing out the sim
pie fact that the mariner did have
all the time, another known point
on the face Of the earth, to-wit
namely, the North Pole. He had
but to look at his magnetic COM
pass, the sole reliance Of mariners
for so many years, and he could
draw another line of his triangle
due north from him. He could
then draw two lines of his triangle
as before. He had all the materials
necessary for finding his position
no matter whether he could see the
stars or not.
This method has been pronounc.
ed sound by the expert navigators
Of the navy department and has
been published by them, unde- the
signature Of Clements. 1t has no,
been used to any great extent as
yet. but its practical usefulness
seems certain. And its potentia,
value can scarcely be overestimat-
ed. For ignorance Of his position
has always been the curse of the
navigator. This ignorance was
dangerous enough in the old days
when sailing ships ploughed along
at an average of few miles ar
hour. It was not even so bad SC
years ago when seven or eight
knots (about ten miles) an houl
was considered high speed for E
gunboat. But now the fastest de.
stroyers travel at the rate of 81
knots, which is over forty-five
miles an hour. Such vesse
knows the direction in which it i.
going and approximately the speed
as shown by the log. Hence il
knows about where it is. But winds
and ocean currents throw it of Its
course in ways and to extents tina,
cannot be determined. Travelling
at terrific speed, if the sky is over.
cast SO that no observations car
be made with the sextant, a shiI
may soon be practically lost.
This new method makes the ma.
riner forever Independent Of thu
weather and Of the stars. 1t is, Of
course, really the work of man,
men, including those who devised
and perfected the direction-flnder
But perhaps the most remarkable
thing about 1t is that a retired
financier with a taste for trigonom
etry brought it to its highest de.
velopment.