The sun. [volume] (New York [N.Y.]) 1833-1916, 1899-02-19

he says, that at different periods OF the four
seasons, and on the first and last days OF the
month. and at certain hours OF the night and
day. the seas have certain conditions as to the
rising OF their waters and the flow and agita-
ton thereof" This cosmologist went on to say
that, "as 10 the rising OF the waters. It is sup
posed that. when the sun acts upon them, II
rare1est them. and they expand and seek q space
amplert than that wherein they were before, and
the one part repels the other In the Ave direc-
tions. eastward. westward. southwark. north
ward and upward. and there arise. at the same
time. various winds on tho shores OF the sea-.
This 10 what is said as to the cause OF the rising
OF the water" As for the flow OF certain seas
at the time Of the rising OF tho moon.
this was attributed to the alleged fact
that at the bottom OF such seas there are
solid rocks and hard stones. and when the
moon rises over the surface OF such a sea Its
penetrating rays reach these rocks and stones
which are at the bottom. and are then reflected
back thence: the waters are heated and rare
fed and seek an ampler space. and roll in
waves toward the seashore; so 1t continues as
long as the moon chimes in midheaven. When
she begins to decline the boiling OF the water
ceases. and the particles cool and become
dense and return to their state Of rest. and the
currents run according to their wont. This
goes on until the moon reaches the western
horizon. when the flow begins again, as it did
when the moon was in the eastern horizon.
The flow continues until the moon is at the
middle OF the sky below the horizon. when 1t
ceases. Then. when the moon comes upward.
the flow begins again. until she reaches the
eastern horizon. This is the account OF the flow
and ebb OF the sea- The agitation of tho sea
Is then compared by this Mohammedan writer
to "the agitation OF the humors in mems
| bodies. for, verify. as thou seest, in the case
Of a sanguine or bilious man. these humors
stirring in his body and then subsiding little
by little. 80, likewise, the sea has matters
| which rise from time to time as they gain
strength. whereby 1t is thrown into violent
commotion. which subsidies little by little.
This the Prophet ION whom be the blessings of
God and his peace) hath expressed in a ~poetical
manner when he says: Verify the Angel. who
is set over the seas. places his foot in the sea.
and thence comes the low; then he raises it.
and thence comes the obj" At Prof. parwin's
request. Mr.. Magnusson searched the old
Icelandio literature for references to the
tides. In the RimbeRla he found this passage:
" Beda, the priest. says that the tides follow
the moon. and that they ebb through her glow
ing on them. but wax in consequence Of her
movement" And again: AT new moon the
moon stands in the way OF the sun and pre-
vents him from drying up the sea: she also
drops down her own moisture. For both these
reasons. at every new moon the ocean swells
and makes those tides which we call spring
tides. But when the moon gets past the sun
the latter throws down some Of his heat upon
the sea. and diminishes thereby the fluidity
OF the water. In this way the tides Of
the sea are lessened.' In another passage,
the same author writes: But when the moon
is opposite to the sun the sun heats the ocean
greatly. and. as nothing impedes that warmth.
the ocean boils and the s~ea-fiood is more i'm
petuous than before: Just as one may see
water rise In a kettle when 1t boils violently.
This we call spring tide" Prof. Darwin points
out tho Inconsistency In explaining one spring
tide by the Interruption OF the suns heat by
the moon. and the next one by the excess of
that heat.
The Greeks and Romans. living as they did
on the shores OF the almost tideless Mediter-
ranean. had not much occasion to learn about
the tides. The only classical author who
treats OF the phenomenon in any detail is
Posidonius. and. for our knowledge OF his
work. we have to rely entirely on quotations
from him by Strabo. Posidonius says that
Aristotle attributed the flow and ebb OF the sea
at Cadiz (outside the Mediterranean to the
mountainous formation Of the coast. but this
he pronounces nonsense. particularly as the
coast OF Spain is fiat and sandy. He himself
attributed the tides to the moons influence.
and the accuracy Of his observations is proved
by the following passage from Strabo: "Posido-
MUS asserts that the movement of the ocean
observes a regular series like a heavenly body,
there being a daily. monthly. and yearly
movement. according to the influence Of
the moon. For. when the moon is above the
eastern horizon by the distance of one sign of
the zodiac Il. @. 300l. the sea begins to flow. and
encroaches visibly on the land until the moon
reaches the meridian. When she has passed
the meridian the sea, In turn, GIBBS gradually
until the moon ia above the western horizon by
the distance OF one sign OF the zodiac. The
sea then remains motionless. while the moon
Is actually setting. and so continues as long as
the moon is moving beneath the earth as far as
a sign OF the zodiac beneath the horizon. Then
the sea again advances until the moon has
reached the meridian below the earth. and re-
while the moon Is moving toward the
east until she is the distance OF a sign Of the
zodiac below the eastern horizon; the sea re-
mains at rest until the moon is the same dis
lance above the eastern horizon, and then be-
gins to flow again" As to the monthly move
ment OF the tides. Posidonius averred that "the
GIBBS are greatest at the conjunction of the sun
and moon. and then grow less until the time of
nall moon. and increase again until the time OF ,
full moon. and grow less again until the moon
has waned to half. Then the increase OF the ,
tlde tolows until the next conjunction" Posi-
said that he had learned the yearly
Of the tides from the people Of
CadiZ. They had told him that the ebb and flow =
alike were greatest at the summer ~solstice. He
guessed for himself that the tides grow less ,
rom the solstice to the equinox. and then in
crease between the equinox and the winter ,
'olstice. and then grow less until the spring !
equinox. and then greater until the summer !
Prof. Darwin considers this an ex. !
'ellent account OF the tides at CadiE. ,
III. I
Our author quotes another noteworthy PAS ,
'aRe from Strabo. which was unintellipible co !
ong as ignorance prevailed In Europe concern- !
ng tidal phenomena in remoter parts of the :
world. strabo wrote; "Posidonius saws that )