The Billings gazette. [volume] (Billings, Mont.) 1896-1919, 1899-11-17
THE FORCEOF WAVES.
GENTLE ROLLS OF WATER THAT
Held A FEARFUL POWER.

Many visitors to the coast are sorel
puzzled when a boatman either refusG
to put Off from the shore. or at mos
20 far from land, on n day when theg
IL no sign Of nm approaching stor.
and the water Is only moved by a Ion.
and gentle rolling swell,
Argument Is Of no avail, and II tn
old salt Is pushed for a eason he viii
only reply with some cryptogramlc re
mark about 1.-THE ground sea-" thu
Questioner then retiring more Devil
dered than before.
1t is hard to understand how such q
gentle swell car presage danger, but
20 experienced eyes It gives a warning
that must be needed. All along the
west aud parts Of the south coasts of
England and Ireland. as well as the
west coast OF Scotland, %uncounted
tales are told Of ships which on a per.
fectly calm day have been within a
few hours first caught by a gentle roll
of the water and finally thrown on a
rockbound shore by the dreaded
''ground sea-"
To understand this curious marine
phenomenon 1t must be borne In mind
that out on the Atlantic waves are Of.
ten formed to a heigh of 40 feet. Driv-
en- before a heavy gale, these advance
at a rate of from 80 to 40 miles an
hour. Travelling at such a rate, they
soon get out Of the wind swept
area. But ever though, for them, the
storm is past they still roll on In fury.
their undulations often being felt 800
miles from the point Of their creation.
In the region Of the storm these
waves are fierce, breaking pillows, but
as they get farther away they settle
down into long, rolling ridges, which
travel onward In long, unbroken lines.
perfectly parallel with each other.
Out on the open sea these ridges Of.
ten stretch out for q distance of over
30 miles. and they travel In threes,
each successive wave being larger
than Its predecessor. The sight Is an
imposing one.
The farther they progress the small
or they become In height. but this Is
compensated tor by the fact that their
motion Is communicated to the mass OF
water below. until the roll can he de.
tected fully 80 feet under the surface.
This gives them the name Of ground
sea-"
In this popularity their danger lies. |
for when a becalmed ship Is caught In
them, her draft. the resisting power
that enables her to ride out a storm.
becomes the fulcrum which the LIQUID
mass Uses to huri her onward to de.
struction,
On a calm day any sailing craft
caught In the ground sea" near a
rocky shore Is as good as lost, unless a
wind can spring up and enable her to
beat out to sea. Many a ship has met
this fate. The reason many more do
get lost Ia due to the gentle swell
that so deceives a landsman and warns
sailor.
Az the ''ground sea" advances II
pushes q certain amount Of water be.
fore Il. This also forms into ridges,
like Its pursuer, but Of less height and
approximately no depth.
The false sea-" rs It Is called, Ia lit.
lie more than a rolling swell, but 1t
sives a warning Of from 20 minutes to
'wo hours duration, enabling a ship
% either run Into port, get out to sea
'r securely anchor; while at the sen.
'ide resorts the boatmen run close In
'hore to the surprise Of the 'trippers."
When It Is remembered that a wave
70 feet high, which Is often attained by
he ground sea-" strikes with a force
u one ton to the square Inch. the ne.
for caution will be recognized.
All waves that come In parallel
'idges, however, are not dangerous, as
Ia a wind billow" that Is closely
allied to the ground sea" In appear.
ance.
wind pillows" are due to a heavy
wind blowing but a few miles off the
land, but as they have had but n com.
paratlvely short distance to travel they
no depth. Consequently even a
boat is perfectly safe on them
4 properly handled.
These waves usually appear when
here Is a comparative calm near the
shore, their great point Of difference
rom the ground sea-" In appearance
,eing that their unbroken lines are
and are all equidistant. not
travelling in threes.
Generally the wind blow does not
freak Into foam, but occasionally this
happens when they are coming In
Igainst the tide. Then 1t Is hard to de.
them from ordinary waves, the
Of a local wlndstorm. These
ways break into foam at their crest.
he white horses" OF the marine poet,
Remembering these peculiarities of
he various waves will save tourists I
disappointment when wis.
r heads bid them keep to the land,
Or, to them, no apparent reason. while
may keep them from rushing into
Unknown dangers, One other fact is I
lso worthy ct mention. as It may !
rOve Of advantage should n boat drift