a journey in other worlds-第12部分

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exact　speed；　should　the　officers　be　unable　to　judge　it　by　the
eye；　so　there　is　no　danger　of　a　vehicle's　speed　exceeding　that
allowed　in　the　section　in　which　it　happens　to　be；　neither　can　a
slow　one　remain　on　the　fast　lines。
　　　
〃Of　course；　to　make　such　high　speed　for　ordinary　carriages
possible；　a　perfect　pavement　became　a　sine　qua　non。　　We　have
secured　this　by　the　half…inch　sheet　of　steel　spread　over　a
carefully　laid　surface　of　asphalt；　with　but　little　bevel；　and
though　this　might　be　slippery　for　horses'　feet；　it　never
seriously　affects　our　wheels。　　There　being　nothing　harder　than
the　rubber　ties　of　comparatively　light　drays　upon　itfor　the
heavy　traffic　is　carried　by　electric　railways　under　groundit
will　practically　never　wear　out。
　　　
〃With　the　application　of　steel　to　the　entire　surface；　car…tracks
became　unnecessary；　ordinary　wheels　answering　as　well　as　those
with　flanges；　so　that　no　new　tracks　were　laid；　and　finally　the
car　companies　tore　up　the　existing　ones；　selling　them　in　many
instances　to　the　municipalities　as　old　iron。　　Our　streets　also
need　but　little　cleaning；　neither　is　the　surface　continually
indented；　as　the　old　cobble…stones　and　Belgian　blocks　were；　by
the　pounding　of　the　horses'　feet；　so　that　the　substitution　of
electricity　for　animal　power　has　done　much　to　solve　the　problem
of　attractive　streets。
　　　
〃Scarcely　a　ton　of　coal　comes　to　Manhattan　Island　or　its　vicinity
in　a　year。　　Very　little　of　it　leaves　the　mines；　at　the　mouths　of
which　it　is　converted　into　electricity　and　sent　to　the　points　of
consumption　by　wire；　where　it　is　employed　for　all　uses　to　which
fuel　was　put；　and　many　others。　　Consequently　there　is　no　smoke；
and　the　streets　are　not　encumbered　with　coal…carts；　the　entire
width　being　given　up　to　carriages；　etc。　　The　ground　floors　in　the
business　parts　are　used　for　large　warehouses；　trucks　running　in
to　load　and　unload。　　Pedestrians　therefore　have　sidewalks　level
with　the　second　story；　consisting　of　glass　floors　let　into
aluminum　frames；　while　all　street　crossings　are　made　on　bridges。　
Private　houses　have　a　front　door　opening　on　the　　sidewalk；　and
another　on　the　ground　level；　so　that　ladies　paying　visits　or
leaving　cards　can　do　so　in　carriages。　　In　business　streets　the
second　story　is　used　for　shops。　　In　place　of　steel　covering；
country　roads　have　a　thick　coating　of　cement　and　asphalt　over　a
foundation　of　crushed　stone；　giving　a　capital　surface；　and　have　a
width　of　thirty…three　feet　（two　rods）　in　thinly　settled
districts；　to　sixty…six　feet　（four　rods）　where　the　population　is
greater。　　All　are　planted　with　shade　and　fruit　trees；　while　the
wide　driveways　have　one　or　two　broad　sidewalks。　　The　same　rule　of
making　the　slow…moving　vehicles　keep　near　the　outside　prevails；
though　the　rate　of　increase　in　speed　on　approaching　the　middle　is
more　rapid　than　in　cities；　and　there　is　usually　no　dividing
ridge。　　On　reaching　the　top　of　a　long　and　steep　hill；　if　we　do
not　wish　to　coast；　we　convert　the　motors　into　dynamos；　while
running　at　full　speed；　and　so　change　the　kinetic　energy　of　the
descent　into　potential　in　our　batteries。　　This　twentieth…century
stage…coaching　is　one　of　the　delights　to　which　we　are　heirs；
though　horses　are　still　used　by　those　that　prefer　them。
　　　
We　have　been　much　aided　in　our　material　progress　by　the　facility
with　which　we　obtain　the　metals。　　It　was　observed；　some　time　ago；
that　when　artesian　and　oil　wells　had　reached　a　considerable
depth；　what　appeared　to　be　drops　of　lead　and　antimony　came　up
with　the　stream。　　It　finally　occurred　to　a　well…borer　that　if　he
could　make　his　drill　hard　enough　and　get　it　down　far　enough；
keeping　it　cool　by　solidified　carbonic　acid　during　the
proceeding；　he　would　reach　a　point　at　which　most　of　the　metals
would　be　viscous；　if　not　actually　molten；　and　on　being　freed　from
the　pressure　of　the　crust　they　would　expand；　and　reach　the
surface　in　a　stream。　　This　experiment　he　performed　near　the　hot
geysers　in　Yellowstone　Park；　and　what　was　his　delight；　on
reaching　a　depth　scarcely　half　a　mile　beyond　his　usual　stopping…
place；　to　be　rewarded　by　a　stream　of　metal　that　heralded　its
approach　by　a　loud　explosion　and　a　great　rush　of　superheated
steam！　　It　ran　for　a　month；　completely　filling　the　bed　of　a
small；　dried…up　river；　and　when　it　did　stop　there　were　ten
million　tons　in　sight。　　This　proved　the　feasibility　of　the
scheme；　and；　though　many　subsequent　attempts　were　less
successful；　we　have　learned　by　experience　where　it　is　best　to
drill；　and　can　now　obtain　almost　any　metal　we　wish。
　　　
〃'Magnetic　eyes'　are　of　great　use　to　miners　and　Civil　engineers。　
These　instruments　are　something　like　the　mariner's　compass；　with
the　sensitiveness　enormously　increased　by　galvanic　currents。　　The
'eye；'　as　it　were；　sees　what　substances　are　underground；　and　at
what　distances。　　It　also　shows　how　many　people　are　in　an
adjoining　roomthrough　the　magnetic　properties　of　the　iron　in
their　bloodwhether　they　are　moving；　and　in　what　directions　and
at　what　speed　they　go。　　In　connection　with　the　phonograph　and
concealed　by　draperies；　it　is　useful　to　detectives；　who；　through
a　registering　attachment；　can　obtain　a　record　of　everything　said
and　done。
　　　
〃Our　political　system　remains　with　but　little　change。　　Each　State
has　still　two　United　States　Senators；　though　the　population
represented　by　each　representative　has　been　greatly　increased；　so
that　the　Senate　has　grown　numerically　much　more　than　the　House。　
It　is　the　duty　of　each　member　of　Congress　to　understand　the
conditions　existing　in　every　other　member's　State　or　district；
and　the　country's　interest　always　precedes　that　of　party。　　We
have　a　comprehensive　examination　system　in　the　civil　service；　and
every　officeholder；　except　members　of　the　Cabinet；　retains　his
office　while　efficiently　performing　his　duty；　without　regard　to
politics。　　The　President　can　also　be　re…elected　any　number　of
times。　　The　Cabinet　members；　as　formerly；　usually　remain　in
office　while　he　does；　and　appear　regularly　in　Congress　to　defend
their　measures。
　　　
〃The　really　rapid　transit　lines　in　New　York　are　underground；　and
have　six　tracks；　two　being　used　for　freight。　　At　all　stations　the
local　tracks　rise　several　feet　towards　the　street　and　slope　off
in　both　directions；　while　the　express　tracks　do　this　only　at
stations　at　which　the　faster　trains　stop。　　This　gives　the
passengers　a　shorter　distance　to　descend　or　rise　in　the
elevators；　and　the　ascent　before　the　stations　aids　the　brakes　in
stopping；　while　the　drop　helps　the　motors　to　start　the　trains
quickly　in　getting　away。
　　　
〃Photography　has　also　made　great　strides；　and　there　is　now　no
difficulty　in　reproducing　exactly　the　colours　of　the　object
taken。
　　　
〃Telephones　have　been　so　improved　that　one　person　can　speak　in
his　natural　voice　with　another　in　any　part　of　the　globe；　the　wire
that　enables　him　to　hear　also　showing　him　the　face　of　the　speaker
though　he　be　at　the　antipodes。　　All　telephone　wires　being
underground　and　kept　by　themselves；　they　are　not　interfered　with
by　any　high…tension　electric…light　or　power　wires；　thunderstorms；
or　anything　else。
　　　
〃Rain…making　is　another　subject　removed　from　the　uncertainties；