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¡ª¡ª¡ª¡ªÎ´ÔĶÁÍꣿ¼ÓÈëÊéÇ©ÒѱãÏ´μÌÐøÔĶÁ£¡
is¡¡continually¡¡forming¡¡in¡¡it¡¡too¡£
¡¡¡¡Again£»¡¡even¡¡in¡¡the¡¡case¡¡of¡¡the¡¡water¡¡that¡¡is¡¡not¡¡being¡¡formed¡¡from
day¡¡to¡¡day¡¡but¡¡exists¡¡as¡¡such£»¡¡we¡¡must¡¡not¡¡suppose¡¡as¡¡some¡¡do¡¡that
rivers¡¡have¡¡their¡¡source¡¡in¡¡definite¡¡subterranean¡¡lakes¡£¡¡On¡¡the
contrary£»¡¡just¡¡as¡¡above¡¡the¡¡earth¡¡small¡¡drops¡¡form¡¡and¡¡these¡¡join
others£»¡¡till¡¡finally¡¡the¡¡water¡¡descends¡¡in¡¡a¡¡body¡¡as¡¡rain£»¡¡so¡¡too¡¡we
must¡¡suppose¡¡that¡¡in¡¡the¡¡earth¡¡the¡¡water¡¡at¡¡first¡¡trickles¡¡together
little¡¡by¡¡little£»¡¡and¡¡that¡¡the¡¡sources¡¡of¡¡the¡¡rivers¡¡drip£»¡¡as¡¡it¡¡were£»
out¡¡of¡¡the¡¡earth¡¡and¡¡then¡¡unite¡£¡¡This¡¡is¡¡proved¡¡by¡¡facts¡£¡¡When¡¡men
construct¡¡an¡¡aqueduct¡¡they¡¡collect¡¡the¡¡water¡¡in¡¡pipes¡¡and¡¡trenches£»¡¡as
if¡¡the¡¡earth¡¡in¡¡the¡¡higher¡¡ground¡¡were¡¡sweating¡¡the¡¡water¡¡out¡£
Hence£»¡¡too£»¡¡the¡¡head¡waters¡¡of¡¡rivers¡¡are¡¡found¡¡to¡¡flow¡¡from
mountains£»¡¡and¡¡from¡¡the¡¡greatest¡¡mountains¡¡there¡¡flow¡¡the¡¡most
numerous¡¡and¡¡greatest¡¡rivers¡£¡¡Again£»¡¡most¡¡springs¡¡are¡¡in¡¡the
neighbourhood¡¡of¡¡mountains¡¡and¡¡of¡¡high¡¡ground£»¡¡whereas¡¡if¡¡we¡¡except
rivers£»¡¡water¡¡rarely¡¡appears¡¡in¡¡the¡¡plains¡£¡¡For¡¡mountains¡¡and¡¡high
ground£»¡¡suspended¡¡over¡¡the¡¡country¡¡like¡¡a¡¡saturated¡¡sponge£»¡¡make¡¡the
water¡¡ooze¡¡out¡¡and¡¡trickle¡¡together¡¡in¡¡minute¡¡quantities¡¡but¡¡in¡¡many
places¡£¡¡They¡¡receive¡¡a¡¡great¡¡deal¡¡of¡¡water¡¡falling¡¡as¡¡rain¡¡£¨for¡¡it
makes¡¡no¡¡difference¡¡whether¡¡a¡¡spongy¡¡receptacle¡¡is¡¡concave¡¡and
turned¡¡up¡¡or¡¡convex¡¡and¡¡turned¡¡down£º¡¡in¡¡either¡¡case¡¡it¡¡will¡¡contain
the¡¡same¡¡volume¡¡of¡¡matter£©¡¡and£»¡¡they¡¡also¡¡cool¡¡the¡¡vapour¡¡that¡¡rises
and¡¡condense¡¡it¡¡back¡¡into¡¡water¡£
¡¡¡¡Hence£»¡¡as¡¡we¡¡said£»¡¡we¡¡find¡¡that¡¡the¡¡greatest¡¡rivers¡¡flow¡¡from¡¡the
greatest¡¡mountains¡£¡¡This¡¡can¡¡be¡¡seen¡¡by¡¡looking¡¡at¡¡itineraries£º¡¡what
is¡¡recorded¡¡in¡¡them¡¡consists¡¡either¡¡of¡¡things¡¡which¡¡the¡¡writer¡¡has
seen¡¡himself¡¡or¡¡of¡¡such¡¡as¡¡he¡¡has¡¡compiled¡¡after¡¡inquiry¡¡from¡¡those
who¡¡have¡¡seen¡¡them¡£
¡¡¡¡In¡¡Asia¡¡we¡¡find¡¡that¡¡the¡¡most¡¡numerous¡¡and¡¡greatest¡¡rivers¡¡flow¡¡from
the¡¡mountain¡¡called¡¡Parnassus£»¡¡admittedly¡¡the¡¡greatest¡¡of¡¡all
mountains¡¡towards¡¡the¡¡south¡east¡£¡¡When¡¡you¡¡have¡¡crossed¡¡it¡¡you¡¡see¡¡the
outer¡¡ocean£»¡¡the¡¡further¡¡limit¡¡of¡¡which¡¡is¡¡unknown¡¡to¡¡the¡¡dwellers
in¡¡our¡¡world¡£¡¡Besides¡¡other¡¡rivers¡¡there¡¡flow¡¡from¡¡it¡¡the¡¡Bactrus£»¡¡the
Choaspes£»¡¡the¡¡Araxes£º¡¡from¡¡the¡¡last¡¡a¡¡branch¡¡separates¡¡off¡¡and¡¡flows
into¡¡lake¡¡Maeotis¡¡as¡¡the¡¡Tanais¡£¡¡From¡¡it£»¡¡too£»¡¡flows¡¡the¡¡Indus£»¡¡the
volume¡¡of¡¡whose¡¡stream¡¡is¡¡greatest¡¡of¡¡all¡¡rivers¡£¡¡From¡¡the¡¡Caucasus
flows¡¡the¡¡Phasis£»¡¡and¡¡very¡¡many¡¡other¡¡great¡¡rivers¡¡besides¡£¡¡Now¡¡the
Caucasus¡¡is¡¡the¡¡greatest¡¡of¡¡the¡¡mountains¡¡that¡¡lie¡¡to¡¡the¡¡northeast£»
both¡¡as¡¡regards¡¡its¡¡extent¡¡and¡¡its¡¡height¡£¡¡A¡¡proof¡¡of¡¡its¡¡height¡¡is
the¡¡fact¡¡that¡¡it¡¡can¡¡be¡¡seen¡¡from¡¡the¡¡so¡called¡¡'deeps'¡¡and¡¡from¡¡the
entrance¡¡to¡¡the¡¡lake¡£¡¡Again£»¡¡the¡¡sun¡¡shines¡¡on¡¡its¡¡peaks¡¡for¡¡a¡¡third
part¡¡of¡¡the¡¡night¡¡before¡¡sunrise¡¡and¡¡again¡¡after¡¡sunset¡£¡¡Its¡¡extent¡¡is
proved¡¡by¡¡the¡¡fact¡¡that¡¡thought¡¡contains¡¡many¡¡inhabitable¡¡regions
which¡¡are¡¡occupied¡¡by¡¡many¡¡nations¡¡and¡¡in¡¡which¡¡there¡¡are¡¡said¡¡to¡¡be
great¡¡lakes£»¡¡yet¡¡they¡¡say¡¡that¡¡all¡¡these¡¡regions¡¡are¡¡visible¡¡up¡¡to¡¡the
last¡¡peak¡£¡¡From¡¡Pyrene¡¡£¨this¡¡is¡¡a¡¡mountain¡¡towards¡¡the¡¡west¡¡in
Celtice£©¡¡there¡¡flow¡¡the¡¡Istrus¡¡and¡¡the¡¡Tartessus¡£¡¡The¡¡latter¡¡flows
outside¡¡the¡¡pillars£»¡¡while¡¡the¡¡Istrus¡¡flows¡¡through¡¡all¡¡Europe¡¡into
the¡¡Euxine¡£¡¡Most¡¡of¡¡the¡¡remaining¡¡rivers¡¡flow¡¡northwards¡¡from¡¡the
Hercynian¡¡mountains£»¡¡which¡¡are¡¡the¡¡greatest¡¡in¡¡height¡¡and¡¡extent¡¡about
that¡¡region¡£¡¡In¡¡the¡¡extreme¡¡north£»¡¡beyond¡¡furthest¡¡Scythia£»¡¡are¡¡the
mountains¡¡called¡¡Rhipae¡£¡¡The¡¡stories¡¡about¡¡their¡¡size¡¡are¡¡altogether
too¡¡fabulous£º¡¡however£»¡¡they¡¡say¡¡that¡¡the¡¡most¡¡and¡¡£¨after¡¡the¡¡Istrus£©
the¡¡greatest¡¡rivers¡¡flow¡¡from¡¡them¡£¡¡So£»¡¡too£»¡¡in¡¡Libya¡¡there¡¡flow
from¡¡the¡¡Aethiopian¡¡mountains¡¡the¡¡Aegon¡¡and¡¡the¡¡Nyses£»¡¡and¡¡from¡¡the
so¡called¡¡Silver¡¡Mountain¡¡the¡¡two¡¡greatest¡¡of¡¡named¡¡rivers£»¡¡the
river¡¡called¡¡Chremetes¡¡that¡¡flows¡¡into¡¡the¡¡outer¡¡ocean£»¡¡and¡¡the¡¡main
source¡¡of¡¡the¡¡Nile¡£¡¡Of¡¡the¡¡rivers¡¡in¡¡the¡¡Greek¡¡world£»¡¡the¡¡Achelous
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the¡¡Nestus£»¡¡and¡¡the¡¡Hebrus¡¡all¡¡three¡¡from¡¡Scombrus£»¡¡many¡¡rivers£»
too£»¡¡flow¡¡from¡¡Rhodope¡£
¡¡¡¡All¡¡other¡¡rivers¡¡would¡¡be¡¡found¡¡to¡¡flow¡¡in¡¡the¡¡same¡¡way£»¡¡but¡¡we¡¡have
mentioned¡¡these¡¡as¡¡examples¡£¡¡Even¡¡where¡¡rivers¡¡flow¡¡from¡¡marshes£»
the¡¡marshes¡¡in¡¡almost¡¡every¡¡case¡¡are¡¡found¡¡to¡¡lie¡¡below¡¡mountains¡¡or
gradually¡¡rising¡¡ground¡£
¡¡¡¡It¡¡is¡¡clear¡¡then¡¡that¡¡we¡¡must¡¡not¡¡suppose¡¡rivers¡¡to¡¡originate¡¡from
definite¡¡reservoirs£º¡¡for¡¡the¡¡whole¡¡earth£»¡¡we¡¡might¡¡almost¡¡say£»¡¡would
not¡¡be¡¡sufficient¡¡£¨any¡¡more¡¡than¡¡the¡¡region¡¡of¡¡the¡¡clouds¡¡would¡¡be£©¡¡if
we¡¡were¡¡to¡¡suppose¡¡that¡¡they¡¡were¡¡fed¡¡by¡¡actually¡¡existing¡¡water
only¡¡and¡¡it¡¡were¡¡not¡¡the¡¡case¡¡that¡¡as¡¡some¡¡water¡¡passed¡¡out¡¡of
existence¡¡some¡¡more¡¡came¡¡into¡¡existence£»¡¡but¡¡rivers¡¡always¡¡drew
their¡¡stream¡¡from¡¡an¡¡existing¡¡store¡£¡¡Secondly£»¡¡the¡¡fact¡¡that¡¡rivers
rise¡¡at¡¡the¡¡foot¡¡of¡¡mountains¡¡proves¡¡that¡¡a¡¡place¡¡transmits¡¡the
water¡¡it¡¡contains¡¡by¡¡gradual¡¡percolation¡¡of¡¡many¡¡drops£»¡¡little¡¡by
little£»¡¡and¡¡that¡¡this¡¡is¡¡how¡¡the¡¡sources¡¡of¡¡rivers¡¡originate¡£¡¡However£»
there¡¡is¡¡nothing¡¡impossible¡¡about¡¡the¡¡existence¡¡of¡¡such¡¡places
containing¡¡a¡¡quantity¡¡of¡¡water¡¡like¡¡lakes£º¡¡only¡¡they¡¡cannot¡¡be¡¡big
enough¡¡to¡¡produce¡¡the¡¡supposed¡¡effect¡£¡¡To¡¡think¡¡that¡¡they¡¡are¡¡is
just¡¡as¡¡absurd¡¡as¡¡if¡¡one¡¡were¡¡to¡¡suppose¡¡that¡¡rivers¡¡drew¡¡all¡¡their
water¡¡from¡¡the¡¡sources¡¡we¡¡see¡¡£¨for¡¡most¡¡rivers¡¡do¡¡flow¡¡from
springs£©¡£¡¡So¡¡it¡¡is¡¡no¡¡more¡¡reasonable¡¡to¡¡suppose¡¡those¡¡lakes¡¡to
contain¡¡the¡¡whole¡¡volume¡¡of¡¡water¡¡than¡¡these¡¡springs¡£
¡¡¡¡That¡¡there¡¡exist¡¡such¡¡chasms¡¡and¡¡cavities¡¡in¡¡the¡¡earth¡¡we¡¡are¡¡taught
by¡¡the¡¡rivers¡¡that¡¡are¡¡swallowed¡¡up¡£¡¡They¡¡are¡¡found¡¡in¡¡many¡¡parts¡¡of
the¡¡earth£º¡¡in¡¡the¡¡Peloponnesus£»¡¡for¡¡instance£»¡¡there¡¡are¡¡many¡¡such
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In¡¡Greece¡¡this¡¡kind¡¡of¡¡thing¡¡happens¡¡on¡¡quite¡¡a¡¡small¡¡scale£»¡¡but¡¡the
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call¡¡a¡¡sea£»¡¡is¡¡considerable¡£¡¡Many¡¡great¡¡rivers¡¡fall¡¡into¡¡it¡¡and¡¡it¡¡has
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in¡¡size¡¡to¡¡the¡¡Rhodanus¡¡is¡¡swallowed¡¡up¡¡and¡¡appears¡¡again¡¡elsewhere£º
the¡¡Rhodanus¡¡being¡¡a¡¡navigable¡¡river¡£
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correspondingly¡¡in¡¡another£»¡¡the¡¡sea¡¡must¡¡needs¡¡be¡¡affected¡£
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land¡¡anywhere£»¡¡it¡¡necessarily¡¡leaves¡¡that¡¡place¡¡dry¡¡when¡¡it¡¡recedes£»
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and¡¡in¡¡periods¡¡of¡¡time¡¡which¡¡are¡¡so¡¡immense¡¡compared¡¡with¡¡the¡¡length
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the¡¡mouths¡¡of¡¡the¡¡Nile£»¡¡with¡¡the¡¡single¡¡exception¡¡of¡¡that¡¡at
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enjoys¡¡a¡¡period¡¡of¡¡prosperity¡£¡¡For¡¡these¡¡places¡¡dry¡¡up¡¡and¡¡come¡¡to
be¡¡in¡¡good¡¡condition¡¡while¡¡the¡¡places¡¡that¡¡were¡¡formerly¡¡well¡tempered