industrial biography-第52章

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the　greatest　care　errors　were　unavoidable　and　numerous。　　Thus　in　a

multipltcation…table　prepared　by　a　man　so　eminent　as　Dr。　Hutton　for

the　Board　of　Longitude；　no　fewer　than　forty　errors　were　discovered　in

a　single　page　taken　at　random。　　In　the　tables　of　the　Nautical　Almanac；

where　the　greatest　possible　precision　was　desirable　and　necessary；

more　than　five　hundred　errors　were　detected　by　one　person；　and　the

Tables　of　the　Board　of　Longitude　were　found　equally　incorrect。　　But

such　errors　were　impossible　to　be　avoided　so　long　as　the　ordinary

modes　of　calculating；　transcribing；　and　printing　continued　in　use。



The　earliest　and　simplest　form　of　calculating　apparatus　was　that

employed　by　the　schoolboys　of　ancient　Greece；　called　the　Abacus；

consisting　of　a　smooth　board　with　a　narrow　rim；　on　which　they　were

taught　to　compute　by　means　of　progressive　rows　of　pebbles；　bits　of

bone　or　ivory；　or　pieces　of　silver　coin；　used　as　counters。　　The　same

board；　strewn　over　with　sand；　was　used　for　teaching　the　rudiments　of

writing　and　the　principles　of　geometry。　　The　Romans　subsequently

adopted　the　Abacus；　dividing　it　by　means　of　perpendicular　lines　or

bars；　and　from　the　designation　of　calculus　which　they　gave　to　each

pebble　or　counter　employed　on　the　board；　we　have　derived　our　English

word　to　calculate。　　The　same　instrument　continued　to　be　employed

during　the　middle　ages；　and　the　table　used　by　the　English　Court　of

Exchequer　was　but　a　modified　form　of　the　Greek　Abacus；　the　chequered

lines　across　it　giving　the　designation　to　the　Court；　which　still

survives。　　Tallies；　from　the　French　word　tailler　to　cut；　were　another

of　the　mechanical　methods　employed　to　record　computations；　though　in

a　very　rude　way。　　Step　by　step　improvements　were　made；　the　most

important　being　that　invented　by　Napier　of　Merchiston；　the　inventor

of　logarithms；　commonly　called　Napier's　bones；　consisting　of　a　number

of　rods　divided　into　ten　equal　squares　and　numbered；　so　that　the

whole　when　placed　together　formed　the　common　multiplication　table。　　By

these　means　various　operations　in　multiplication　and　division　were

performed。　　Sir　Samuel　Morland；　Gunter；　and　Lamb　introduced　other

contrivances；　applicable　to　trigonometry；　Gunter's　scale　being　still

in　common　use。　　The　calculating　machines　of　Gersten　and　Pascal　were　of

a　different　kind；　working　out　arithmetical　calculations　by　means　of

trains　of　wheels　and　other　arrangements；　and　that　contrived　by　Lord

Stanhope　for　the　purpose　of　verifying　his　calculations　with　respect

to　the　National　Debt　was　of　like　character。　　But　none　of　these　will

bear　for　a　moment　to　be　compared　with　the　machine　designed　by　Mr。

Babbage　for　performing　arithmetical　calculations　and　mathematical

analyses；　as　well　as　for　recording　the　calculations　when　made；

thereby　getting　rid　entirely　of　individual　error　in　the　operations　of

calculation；　transcription；　and　printing。



The　French　government；　in　their　desire　to　promote　the　extension　of

the　decimal　system；　had　ordered　the　construction　of　logarithmical

tables　of　vast　extent；　but　the　great　labour　and　expense　involved　in

the　undertaking　prevented　the　design　from　being　carried　out。　　It　was

reserved　for　Mr。　Babbage　to　develope　the　idea　by　means　of　a　machine

which　he　called　the　Difference　Engine。　　This　machine　is　of　so

complicated　a　character　that　it　would　be　impossible　for　us　to　give

any　intelligible　description　of　it　in　words　。　　Although　Dr。　Lardner

was　unrivalled　in　the　art　of　describing　mechanism；　he　occupied

twenty…five　pages　of　the　'Edinburgh　Review'　（vol。59）　in　endeavouring

to　describe　its　action；　and　there　were　several　features　in　it　which

he　gave　up　as　hopeless。　　Some　parts　of　the　apparatus　and　modes　of

action　are　indeed　extraordinary　and　perhaps　none　more　so　than　that

for　ensuring　accuracy　in　the　calculated　results；the　machine

actually　correcting　itself；　and　rubbing　itself　back　into　accuracy；

when　the　disposition　to　err　occurs；　by　the　friction　of　the　adjacent

machinery！　　When　an　error　is　made；　the　wheels　become　locked　and　refuse

to　proceed；　thus　the　machine　must　go　rightly　or　not　at　all；an

arrangement　as　nearly　resembling　volition　as　anything　that　brass　and

steel　are　likely　to　accomplish。



This　intricate　subject　was　taken　up　by　Mr。　Babbage　in　1821；　when　he

undertook　to　superintend　for　the　British　government　the　construction

of　a　machine　for　calculating　and　printing　mathematical　and

astronomical　tables。　　The　model　first　constructed　to　illustrate　the

nature　of　his　invention　produced　figures　at　the　rate　of　44　a　minute。

In　1823　the　Royal　Society　was　requested　to　report　upon　the　invention；

and　after　full　inquiry　the　committee　recommended　it　as　one　highly

deserving　of　public　encouragement。　　A　sum　of　1500L。　was　then　placed　at

Mr。　Babbage's　disposal　by　the　Lords　of　the　Treasury　for　the　purpose

of　enabling　him　to　perfect　his　invention。　　It　was　at　this　time　that　he

engaged　Mr。　Clement　as　draughtsman　and　mechanic　to　embody　his　ideas

in　a　working　machine。　　Numerous　tools　were　expressly　contrived　by　the

latter　for　executing　the　several　parts；　and　workmen　were　specially

educated　for　the　purpose　of　using　them。　　Some　idea　of　the　elaborate

character　of　the　drawings　may　be　formed　from　the　fact　that　those

required　for　the　calculating　machinery　alonenot　to　mention　the

printing　machinery；　which　was　almost　equally　elaboratecovered　not

less　than　four　hundred　square　feet　of　surface！　　The　cost　of　executing

the　calculating　machine　was　of　course　very　great；　and　the　progress　of

the　work　was　necessarily　slow。　　The　consequence　was　that　the

government　first　became　impatient；　and　then　began　to　grumble　at　the

expense。　　At　the　end　of　seven　years　the　engineer's　bills　alone　were

found　to　amount　to　nearly　7200L。；　and　Mr。　Babbage's　costs　out　of

pocket　to　7000L。　more。　　In　order　to　make　more　satisfactory　progress；

it　was　determined　to　remove　the　works　to　the　neighbourhood　of　Mr。

Babbage's　own　residence；　but　as　Clement's　claims　for　conducting　the

operations　in　the　new　premises　were　thought　exorbitant；　and　as　he

himself　considered　that　the　work　did　not　yield　him　the　average　profit

of　ordinary　employment　in　his　own　trade；　he　eventually　withdrew　from

the　enterprise；　taking　with　him　the　tools　which　he　had　constructed

for　executing　the　machine。　　The　government　also　shortly　after　withdrew

from　it；　and　from　that　time　the　scheme　was　suspended；　the　Calculating

Engine　remaining　a　beautiful　but　unfinished　fragment　of　a　great　work。

Though　originally　intended　to　go　as　far　as　twenty　figures；　it　was

only　completed　to　the　extent　of　being　capable　of　calculating　to　the

depth　of　five　figures；　and　two　orders　of　differences；　and　only　a

small　part　of　the　proposed　printing　machinery　was　ever　made。　　The

engine　was　placed　in　the　museum　of　King's　College　in　1843；　enclosed

in　a　glass　case；　until　the　year　1862；　when　it　was　removed　for　a　time

to　the　Great　Exhibition；　where　it　formed　perhaps　the　most　remarkable

and　beautifully　executed　piece　of　mechanism　the　combined　result　of

intellectual　and　mechanical　contrivancein　the　entire　collection。*

　＇footnote。。。

A　complete　account　of　the　calculating　machine；　as　well　as　of　an

analytical　engine　afterwards　contrived　by　Mr。　Babbage；　of　still

greater　power　than　the　other；　will　be　found　in　the　Bibliotheque

Universelle　de　Geneve；　of　which　a　translation　into　English；　with

copious　original　notes；　by　the　late　Lady　Lovelace；　daughter　of　Lord

Byron；　was　published　in　the　3rd　vol。　of　Taylor's　Scientific　Memoirs

（London；　1843）。　　A　history　of　the　machine；　and　of　the　circumstances

connected　with　its　construction；　will　also　be　found　in　Weld's　History

of　the　Royal　Society；　vol。　ii。　369…391。　　It　remains　to　be　added；　that

the　perusal　by　Messrs。　Scheutz　of　Stockholm　of　Dr。　Lardner's　account

of　Mr。　Babbage's　engine　in　the　Edinburgh　Review；　led　those　clever

mechanics　to　enter　upon　the　scheme　of　constructing　and　completing　it；

and　the　result　is；　that　their　machine　not　only　calculates　the　tables；

but　prints　the　results。　　It　took　them　nearly　twenty　years　to　perfect

it；　but　when　completed　the　machine　seemed　to　be　almost　capable　of

thinking。　　The　original　was　exhibited　at　the　Paris　Exhibition　of　1855。

A　copy　of　it　has　since　been　secured　by　the　English　government　at　a

cost　of　1200L。；　and　it　is　now　busily　employed　at　Somerset　House　in

working　out　annuity　and　other　tables　for　the　Registrar…General。　　The

copy　was　constructed；　with　several　admirable　improvements；　by　the

Messrs。　Donkin；　the　well…known　mechanical　engineers；　after　the

working　drawings　of　the　Messrs。　Scheutz。

　。。。＇



Clement　was　on　various　other　occasions　invited　to　undertake　work

requiring　extra　skill；　which　other　mechanics　were　unwilling　or　unable

to　execute。　　He　was　thus　always　full　of　employment；　never　being　under

the　necessity　of　canvassing　for　customers。　　He　was　almost　constantly

in　his　workshop；　in　which　he　took　great　pride。　　His　dwelling　was　over

the　office　in　the　yard；　and　it　was　with　difficulty　he　could　be

induced　to　leave　the　premises。　　On　one　occasion　Mr。　Brunel　of　the

Great　Western　Railway　called　upon　him　to　ask　if　he　could　supply　him

with　a　superior　steam…whistle　for　his　locomotives；　the　whistles　which

they　were　using　giving　forth　very　little　sound。　　Clement　examined　the

specimen　brought　by　Brunel；　and　pronounced　it　to　be　〃mere

tallow…chandler's　work。〃　　He　undertook　to　supply　a　proper　article；　and

after　his　usual　fashion　he　proceeded　to　contrive　a　machine　or　tool

for　the　express　purpose　of　making　steam…whistles。　　They　were　made　and

supplied；　and　when　mounted　on　the　locomotive　the　effect　was　indeed

〃screaming。〃　　They　were　heard　miles　off；　and　Brunel；　delighted；

ordered　a　hundred。　　But　when　the　bill　came　in；　it　was　found　that　the

charge　made　for　them　was　very　highas　much　as　40L。　the　set。　　The

company　demurred　at　the　price；Brunel　declaring　it　to　be　six　times

more　than　the　price　they　had　before　been　paying。　　〃That　may　be；〃

rejoined　Clement；　〃but　mine　are　more　than　six　times　better。　　You

ordered　a　first…rate　article；　and　you　must　be　content　to　pay　for　it。〃

The　matter　was　referred　to　an　arbitrator；　who　awarded　the　full　sum

claimed。　　Mr。　Weld　mentions　a　similar　case　of　an　order　which　Clement

received　from　America　to　make　a　large　screw　of　given　dimensions　〃in

the　best　possible　manner；〃　and　he　accordingly　proceeded　to　make　one

with　the　greatest　mathematical　accuracy。　　But　his　bill　amounted　to

some　hundreds　of　pounds；　which　completely　staggered　the　American；　who

did　not　calculate　on　having　to　pay　more　than　20L。　at　the　utmost　for

the　screw。　　The　matter　was；　however；　referred　to　arbitrators；　who　gave

their　decision；　as　in　the　former　case；　in　favour　of　the　mechanic。*

　＇footnote。。。

History　of　the　Royal　Society；　ii。　374。

　。。。＇



One　of　the　last　works　which　Clement　executed　as　a　matter　of　pleasure；

was　the　building　of　an　organ　for　his　own　use。　　It　will　be　remembered

that　when　working　as　a　slater　at　Great　Ashby；　he　had　made　flutes　and