men of invention and industry-第23章

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in　the　name　of　the　Royal　Society　of　London　for　the　improving　of

natural　knowledge；　present　you　with　this　small　but　faithful　token

of　their　regard　and　esteem。　　I　do；　in　their　name　congratulate　you

upon　the　successes　you　have　already　had；　and　I　most　sincerely

wish　that　all　your　future　trials　may　in　every　way　prove

answerable　to　these　beginnings；　and　that　the　full　accomplishment

of　your　great　undertaking　may　at　last　be　crowned　with　all　the

reputation　and　advantage　to　yourself　that　your　warmest　wishes　may

suggest；　and　to　which　so　many　years　so　laudably　and　so　diligently

spent　in　the　improvement　of　those　talents　which　God　Almighty　has

bestowed　upon　you；　will　so　justly　entitle　your　constant　and

unwearied　perseverance。〃



Mr。　Folkes；　in　his　speech；　spoke　of　Mr。　Harrison　as　〃one　of　the

most　modest　persons　he　had　ever　known。　　In　speaking；〃　he

continued；　〃of　his　own　performances；　he　has　assured　me　that；　from

the　immense　number　of　diligent　and　accurate　experiments　he　has

made；　and　from　the　severe　tests　to　which　he　has　in　many　ways　put

his　instrument；　he　expects　he　shall　be　able　with　sufficient

certainty；　through　all　the　greatest　variety　of　seasons　and　the

most　irregular　motions　of　the　sea；　to　keep　time　constantly；

without　the　variation　of　so　much　as　three　seconds　in　a　week；　a

degree　of　exactness　that　is　astonishing　and　even　stupendous；

considering　the　immense　number　of　difficulties；　and　those　of　very

different　sorts；　which　the　author　of　these　inventions　must　have

had　to　encounter　and　struggle　withal。〃



Although　it　is　common　enough　now　to　make　first…rate

chronometers　sufficient　to　determine　the　longitude　with　almost

perfect　accuracy　in　every　clime　of　the　worldit　was　very

different　at　that　time；　when　Harrison　was　occupied　with　his

laborious　experiments。　　Although　he　considered　his　third　machine

to　be　the　ne　plus　ultra　of　scientific　mechanism；　he　nevertheless

proceeded　to　construct　a　fourth　timepiece；　in　the　form　of　a

pocket　watch　about　five　inches　in　diameter。　　He　found　the

principles　which　he　had　adopted　in　his　larger　machines　applied

equally　well　in　the　smaller；　and　the　performances　of　the　last

surpassed　his　utmost　expectations。　　But　in　the　meantime；　as　his

third　timekeeper　was；　in　his　opinion；　sufficient　to　supply　the

requirements　of　the　Board　of　Longitude　as　respected　the　highest

reward　offered；　he　applied　to　the　Commissioners　for　leave　to　try

that　instrument　on　board　a　royal　ship　to　some　port　in　the　West

Indies；　as　directed　by　the　statute　of　Queen　Anne。



Though　Harrison's　third　timekeeper　was　finished　about　the　year

1758；　it　was　not　until　March　12；　1761；　that　he　received　orders

for　his　son　William　to　proceed　to　Portsmouth；　and　go　on　board　the

Dorsetshire　man…of…war；　to　proceed　to　Jamaica。　　But　another

tedious　delay　occurred。　　The　ship　was　ordered　elsewhere；　and

William　Harrison；　after　remaining　five　months　at　Portsmouth；

returned　to　London。　　By　this　time；　John　Harrison　had　finished　his

fourth　timepiecethe　small　one；　in　the　form　of　a　watch。　　At

length　William　Harrison　set　sail　with　this　timekeeper　from

Portsmouth　for　Jamaica；　on　November　18th；　1761；　in　the　Deptford

man…of…war。　　The　Deptford　had　forty…three　ships　in　convoy；　and

arrived　at　Jamaica　on　the　l9th　of　January；　1762；　three　days

before　the　Beaver；　another　of　His　Majesty's　ships…of…war；　which

had　sailed　from　Portsmouth　ten　days　before　the　Deptford；　but　had

lost　her　reckoning　and　been　deceived　in　her　longitude；　having

trusted　entirely　to　the　log。　　Harrison's　timepiece　had　corrected

the　log　of　the　Deptford　to　the　extent　of　three　degrees　of

longitude；　whilst　several　of　the　ships　in　the　fleet　lost　as　much

as　five　degrees！　　This　shows　the　haphazard　way　in　which

navigation　was　conducted　previous　to　the　invention　of　the　marine

chronometer。



When　the　Deptford　arrived　at　Port　Royal；　Jamaica；　the　timekeeper

was　found　to　be　only　five　and　one　tenth　seconds　in　error；　and

during　the　voyage　of　four　months；　on　its　return　to　Portsmouth　on

March　26th；　1762；　it　was　found　（after　allowing　for　the　rate　of

gain　or　loss）　to　have　erred　only　one　minute　fifty…four　and　a　half

seconds。　　In　the　latitude　of　Portsmouth　this　only　amounted　to

eighteen　geographical　miles；　whereas　the　Act　had　awarded　that　the

prize　should　be　given　where　the　longitude　was　determined　within

the　distance　of　thirty　geographical　miles。　　One　would　have

thought　that　Harrison　was　now　clearly　entitled　to　his　reward　of

20；000L。



Not　at　all！　　The　delays　interposed　by　Government　are　long　and

tedious；　and　sometimes　insufferable。　　Harrison　had　accomplished

more　than　was　needful　to　obtain　the　highest　reward　which　the

Board　of　Longitude　had　publicly　offered。　　But　they　would　not

certify　that　he　had　won　the　prize。　　On　the　contrary；　they　started

numerous　objections；　and　continued　for　years　to　subject　him　to

vexatious　delays　and　disappointments。　　They　pleaded　that　the

previous　determination　of　the　longitude　of　Jamaica　by

astronomical　observation　was　unsatisfactory；　that　there　was　no

proof　of　the　chronometer　having　maintained　a　uniform　rate　during

the　voyage；　and　on　the　17th　of　August；　1762；　they　passed　a

resolution；　stating　that　they　〃were　of　opinion　that　the

experiments　made　of　the　watch　had　not　been　sufficient　to

determine　the　longitude　at　sea。〃



It　was　accordingly　necessary　for　Harrison　to　petition　Parliament

on　the　subject。　　Three　reigns　had　come　and　gone　since　the　Act　of

Parliament　offering　the　reward　had　been　passed。　　Anne　had　died；

George　I。　and　George　II。　had　reigned　and　died；　and　now；　in　the

reign　of　George　III。thirty…five　years　after　Harrison　had　begun

his　labours；　and　after　he　had　constructed　four　several　marine

chronometers；　each　of　which　was　entitled　to　win　the　full

prize；an　Act　of　Parliament　was　passed　enabling　the　inventor　to

obtain　the　sum　of　5000L。　as　part　of　the　reward。　　But　the

Commissioners　still　hesitated。　　They　differed　about　the　tempering

of　the　springs。　　They　must　have　another　trial　of　the　timekeeper；

or　anything　with　which　to　put　off　a　settlement　of　the　claim。　

Harrison　was　ready　for　any　further　number　of　trials；　and　in　the

meantime　the　Commissioners　merely　paid　him　a　further　sum　on

account。



Two　more　dreary　years　passed。　　Nothing　was　done　in　1763　except　a

quantity　of　interminable　talk　at　the　Board　of　Commissioners。　　At

length；　on　the　28th　of　March；　1764；　Harrison's　son　again　departed

with　the　timekeeper　on　board　the　ship　Tartar　for　Barbadoes。　　He

returned　in　about　four　months；　during　which　time　the　instrument

enabled　the　longitude　to　be　ascertained　within　ten　miles；　or

one…third　of　the　required　geographical　distance。　　Harrison

memorialised　the　Commissioners　again　and　again；　in　order　that　he

might　obtain　the　reward　publicly　offered　by　the　Government。



At　length　the　Commissioners　could　no　longer　conceal　the　truth。　

In　September；1764；　they　virtually　recognised　Harrison's　claim　by

paying　him　1000L。　on　account；　and；　on　the　9th　of　February；1765；

they　passed　a　resolution　setting　forth　that　they　were

〃unanimously　of　opinion　that　the　said　timekeeper　has　kept　its

time　with　sufficient　correctness；　without　losing　its　longitude　in

the　voyage　from　Portsmouth　to　Barbadoes　beyond　the　nearest　limit

required　by　the　Act　l2th　of　Queen　Anne；　but　even　considerably

within　the　same。〃　　Yet　they　would　not　give　Harrison　the　necessary

certificate；　though　they　were　of　opinion　that　he　was　entitled　to

be　paid　the　full　reward！



It　is　pleasant　to　contrast　the　generous　conduct　of　the　King　of

Sardinia　with　the　procrastinating　and　illiberal　spirit　which

Harrison　met　with　in　his　own　country。　　During　the　same　year　in

which　the　above　resolution　was　passed；　the　Sardinian　minister

ordered　four　of　Harrison's　timekeepers　at　the　price　of　1000L。　

each；　at　the　special　instance　of　the　King　of　Sardinia　〃as　an

acknowledgement　of　Mr。　Harrison's　ingenuity；　and　as　some

recompense　for　the　time　spent　by　him　for　the　general　good　of

mankind。〃　　This　grateful　attention　was　all　the