men of invention and industry-第18章

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the　sun；　moon；　and　planets；　so　as　to　fix　a　vessel's　actual

position　when　far　out　of　sight　of　land；　enabling　long　voyages　to

be　safely　made；　the　marvellous　improvements　in　ship…building；

which　shortened　passages　by　sailing　vessels；　and　vastly　reduced

freights　even　before　steam　gave　an　independent　force　to　the

carriereach　and　all　were　done　by　small　advances；　which　together

contributed　to　the　general　movement　of　mankind。。。。　　Each　owes　all

to　the　others。　　The　forgotten　inventors　live　for　ever　in　the

usefulness　of　the　work　they　have　done　and　the　progress　they　have

striven　for。〃H。　M。　Hyndman。



One　of　the　most　extraordinary　things　connected　with　Applied

Science　is　the　method　by　which　the　Navigator　is　enabled　to　find

the　exact　spot　of　sea　on　which　his　ship　rides。　　There　may　be

nothing　but　water　and　sky　within　his　view；　he　may　be　in　the　midst

of　the　ocean；　or　gradually　nearing　the　land；　the　curvature　of　the

globe　baffles　the　search　of　his　telescope；　but　if　he　have　a

correct　chronometer；　and　can　make　an　astronomical　observation；　he

may　readily　ascertain　his　longitude；　and　know　his　approximate

positionhow　far　he　is　from　home；　as　well　as　from　his　intended

destination。　　He　is　even　enabled；　at　some　special　place；　to　send

down　his　grappling…irons　into　the　sea；　and　pick　up　an　electrical

cable　for　examination　and　repair。



This　is　the　result　of　a　knowledge　of　Practical　Astronomy。　　〃Place

an　astronomer；〃　says　Mr。　Newcomb；　〃on　board　a　ship；　blindfold

him；　carry　him　by　any　route　to　any　ocean　on　the　globe；　whether

under　the　tropics　or　in　one　of　the　frigid　zones；　land　him　on　the

wildest　rock　that　can　be　found；　remove　his　bandage；　and　give　him

a　chronometer　regulated　to　Greenwich　or　Washington　time；　a

transit　instrument　with　the　proper　appliances；　and　the　necessary

books　and　tables；　and　in　a　single　clear　night　he　can　tell　his

position　within　a　hundred　yards　by　observations　of　the　stars。　

This；　from　a　utilitarian　point　of　view；　is　one　of　the　most

important　operations　of　Practical　Astronomy。〃＇2＇



The　Marine　Chronometer　was　the　outcome　of　the　crying　want　of　the

sixteenth　century　for　an　instrument　that　should　assist　the

navigator　to　find　his　longitude　on　the　pathless　ocean。　　Spain　was

then　the　principal　naval　power；　she　was　the　most　potent　monarchy

in　Europe；　and　held　half　America　under　her　sway。　　Philip　III。　

offered　100；000　crowns　for　any　discovery　by　means　of　which　the

longitude　might　be　determined　by　a　better　method　than　by　the　log；

which　was　found　very　defective。　　Holland　next　became　a　great

naval　power；　and　followed　the　example　of　Spain　in　offering　30；000

florins　for　a　similar　discovery。　　But　though　some　efforts　were

made；　nothing　practical　was　done；　principally　through　the

defective　state　of　astronomical　instruments。　　England　succeeded

Spain　and　Holland　as　a　naval　power；　and　when　Charles　II。

established　the　Greenwich　Observatory；　it　was　made　a　special

point　that　Flamsteed；　the　Astronomer…Royal；　should　direct　his

best　energies　to　the　perfecting　of　a　method　for　finding　the

longitude　by　astronomical　observations。　　But　though　Flamsteed；

together　with　Halley　and　Newton；　made　some　progress；　they　were

prevented　from　obtaining　ultimate　success　by　the　want　of

efficient　chronometers　and　the　defective　nature　of　astronomical

instruments。



Nothing　was　done　until　the　reign　of　Queen　Anne；　when　a　petition

was　presented　to　the　Legislature　on　the　25th　of　May；　1714；　by

〃several　captains　of　Her　Majesty's　ships；　merchants　in　London；

and　commanders　of　merchantmen；　in　behalf　of　themselves；　and　of

all　others　concerned　in　the　navigation　of　Great　Britain；〃　setting

forth　the　importance　of　the　accurate　discovery　of　the　longitude；

and　the　inconvenience　and　danger　to　which　ships　were　subjected

from　the　want　of　some　suitable　method　of　discovering　it。　　The

petition　was　referred　to　a　committee；　which　took　evidence　on　the

subject。　　It　appears　that　Sir　Isaac　Newton；　with　his

extraordinary　sagacity；　hit　the　mark　in　his　report。　　〃One　is；〃　he

said；　〃by　a　watch　to　keep　time　exactly；　but；　by　reason　of　the

motion　of　a　ship；　and　the　variation　of　heat　and　cold；　wet　and

dry；　and　the　difference　of　gravity　in　different　latitudes；　such　a

watch　hath　not　yet　been　made。〃



An　Act　was　however　passed　in　the　Session　of　1714；　offering　a　very

large　public　reward　to　inventors：　10；000L。　to　any　one　who　should

discover　a　method　of　determining　the　longitude　to　one　degree　of　a

great　circle；　or　60　geographical　miles；　15；000L。　if　it　determined

the　same　to　two…thirds　of　that　distance；　or　40　geographical

miles；　and　20；000L。　if　it　determined　the　same　to　one…half　of　the

same　distance；　or　30　geographical　miles。　　Commissioners　were

appointed　by　the　same　Act；　who　were　instructed　that　〃one　moiety

or　half　part　of　such　reward　shall　be　due　and　paid　when　the　said

commissioners；　or　the　major　part　of　them；　do　agree　that　any　such

method　extends　to　the　security　of　ships　within　80　geographical

miles　of　the　shore；　which　are　places　of　the　greatest　danger；　and

the　other　moiety　or　half　part　when　a　ship；　by　the　appointment　of

the　said　commissioners；　or　the　major　part　of　them；　shall　actually

sail　over　the　ocean；　from　Great　Britain　to　any　such　port　in　the

West　Indies　as　those　commissioners；　or　the　major　part　of　them；

shall　choose　or　nominate　for　the　experiment；　without　losing　the

longitude　beyond　the　limits　before　mentioned。〃



The　terms　of　this　offer　indicate　how　great　must　have　been　the

risk　and　inconvenience　which　it　was　desired　to　remedy。　　Indeed；

it　is　almost　inconceivable　that　a　reward　so　great　could　be　held

out　for　a　method　which　would　merely　afford　security　within　eighty

geographical　miles！



This　splendid　reward　for　a　method　of　discovering　the　longitude

was　offered　to　the　worldto　inventors　and　scientific　men　of　all

countries　without　restriction　of　race；　or　nation；　or　language。　

As　might　naturally　be　expected；　the　prospect　of　obtaining　it

stimulated　many　ingenious　men　to　make　suggestions　and　contrive

experiments；　but　for　many　years　the　successful　construction　of　a

marine　time…keeper　seemed　almost　hopeless。　　At　length；　to　the

surprise　of　every　one；　the　prize　was　won　by　a　village

carpentera　person　of　no　school；　or　university；　or　college

whatever。



Even　so　distinguished　an　artist　and　philosopher　as　Sir

Christopher　Wren　was　engaged；　as　late　in　his　life　as　the　year

1720；　in　attempting　to　solve　this　important　problem。　　As　has　been

observed；　in　the　memoir　of　him　contained　in　the　'Biographia

Britannica；'＇3＇　〃This　noble　invention；　like　some　others　of　the

most　useful　ones　to　human　life；　seems　to　be　reserved　for　the

peculiar　glory　of　an　ordinary　mechanic；　who；　by　indefatigable

industry；　under　the　guidance　of　no　ordinary　sagacity；　hath

seemingly　at　last　surmounted　all　difficulties；　and　brought　it　to

a　most　unexpected　degree　of　perfection。〃　　Where　learning　and

science　failed；　natural　genius　seems　to　have　triumphed。



The　truth　is；　that　the　great　mechanic；　like　the　great　poet；　is

born；　not　made；　and　John　Harrison；　the　winner　of　the　famous

prize；　was　a　born　mechanic。　　He　did　not；　however；　accomplish　his

object　without　the　exercise　of　the　greatest　skill；　patience；　and

perseverance。　　His　efforts　were　long；　laborious；　and　sometimes

apparently　hopeless。　　Indeed；　his　life；　so　far　as　we　can

ascertain　the　facts；　affords　one　of　the　finest　examples　of

difficulties　encountered　and　triumphantly　overcome；　and　of

undaunted　perseverance　eventually　crowned　by　success；　which　is　to

be　found　in　the　whole　range　of　biography。



No　complete　narrative　of　Harrison's　career　was　ever　written。　

Only　a　short　notice　of　him　appears　in　the　'Biographia

Britannica；'　published　in　1766；　during　his　lifetime'the　facts

of　which　were　obtained　from　himself。　　A　few　notices　of　him　appear

in　the　'Annual　Register；'　also　published　during　his　lifetime。　

The　final　notice　appeared　in　the　volume　published　in　1777；　the

year　after　his　death。　　No　Life　of　him　has　since　appeared。　　Had　he

be