New-York tribune., 1901-06-16

noted a single DIV Of heavy sweI r1-1 seetl
actually exceeds the best average for e. day q
storm. which was Sal feet Nj. Cornish -
marks that n has himself observed a succession
of T.? biiows coming in from the broad Al
iantic at Bournemouth. whose average time in
terval 1875 seconds. from which he coul-
putes the wave length at 1,91S feet, or more than
third of a mile, II is said that period oi
fifteen seconds is not uncommon with westerly
swells on the south coast Of England Sir Co
brel Stokes has seen breakers with an averag-
period Of seventeen seconds. which is equivalent
10 1,4I4 feet good quarter of a mile.
Referring to the well known fact that swell
sometimes arrives before a storm Mr. Cornish
attempts an explanation which is somewhat
complicated. and which is not repeated here. II
is probable that he has forgotten that the rate
at which a storm advances is rarely great
the velocity of winds within il. Tropical hurri
canes often move only FIVE or ten miles hour
hut develop wind velocities Of seventy five or
hundred. Even though the swell thus rafs
did not travel more than forty or fifty miles an
hour it might easily get day or two aheaI r.
the cyclone itself \ well marked diTerence,
though smaller one, might reasonably be *
pected from the average winter storm Of middle
latitudes. which seldom moves faster than thirty
miles hour but is attended with gales blow
ing fifty or sixty.
What interests most people who at safe
distance is not the average height OF waves in
storm. but the elevation attained by the
ceptional bill0w. Whether watch from
sea beach ship. NJ is sure 10 detect eoHsd
cradle inequalities in the size II waves And he
cannot fail 10 notice. too. another significant
phenomenon. Every now and then one wave Of
only moderate dimensions apparently. travels
little faster than its fellows. There otter
two or three sets Of unduations which a sharp
eye distinguish 10y their velocities. Now
when one wave overtakes another. and the Two
merge. an upift Of extra height occurs.
Mr.. Cornish says that he has himself measured
one or two waves in heavy storm which were
al least forty feet high. and probably more He
is prepared To credit the statements made by
sailors that they have seen waves 90 that size
or even fifty feet high. If IL be- distinctly under
stood that these figures represent a frw isolated
examples. and not the average. ". Eertiu, in
his Memoir or the Experimental Study of the
Waves says, we are certain in adopting six
teen metres C5-i- feeU as the maximum limit Of
height" Eut Mr.. Cornish. while not producing
any definite figures, Is prepared 10 believe that
the Frenchman has unders;at,d the case.
NJ Berjin hy the way makes an important
distinction between waves ia the open SEE. ard
those which. striking an isolated rock eighty or
even one hundred feet high. dash clear over it.
Contact With obstacle is ihus recognized as
"a cause which aurmcuts Tho height of a wave
d. this way. perhaps. D. explained tn dtluge
which OCCASIONALLY reaches the crow nest" #
an Liner. fifty or sixty f,at above the deck
and eighty feet above the sea. Eut for It's strik-
ing the fiat side of the vessel iu just the right
manner perhaps the wave might not prove much
bigger than its nrighbors Hut with the proper
combinations ~ circumstances il will develop
startling aspirations.