men of invention and industry-第70节

按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！



discovery　by　Dollond；　in　1758；　of　the　relation　between　the

refractive　and　dispersive　powers　of　different　kinds　of　glass；　and

the　invention　by　that　distinguished　optician　of　the　achromatic

telescope；　the　manufacture　of　that　instrument　had　been　confined

to　England；　where　the　best　flint　glass　was　made。　　But　through　the

short…sighted　policy　of　the　Government；　an　exorbitant　duty　was

placed　upon　the　manufacture　of　flint　glass；　and　the　English　trade

was　almost　entirely　stamped　out。　　We　had　accordingly　to　look　to

foreign　countries　for　the　further　improvement　of　the　achromatic

telescope；　which　Dollond　had　so　much　advanced。



A　humble　mechanic　of　Brenetz；　in　the　Canton　of　Neufchatel；

Switzerland；　named　Guinaud；　having　directed　his　attention　to　the

manufacture　of　flint　glass　towards　the　close　of　last　century；　at

length　succeeded；　after　persevering　efforts；　in　producing　masses

of　that　substance　perfectly　free　from　stain；　and　therefore

adapted　for　the　construction　of　the　object…glasses　of　telescopes。



Frauenhofer；　the　Bavarian　optician；　having　just　begun　business；

heard　of　the　wonderful　success　of　Guinaud；　and　induced　the　Swiss

mechanic　to　leave　Brenetz　and　enter　into　partnership　with　him　at

Munich　in　1805。



The　result　was　perfectly　successful；　and　the　new　firm　turned　out

some　of　the　largest　object…glasses　which　had　until　then　been

made。　　With　one　of　these　instruments；　having　an　aperture　of　9。9

inches；　Struve；　the　Russian　astronomer；　made　some　of　his　greatest

discoveries。　　Frauenhofer　was　succeeded　by　Merz　and　Mahler；　who

carried　out　his　views；　and　turned　out　the　famous　refractors　of

Pulkowa　Observatory　in　Russia；　and　of　Harvard　University　in　the

United　States。　　These　last　two　telescopes　contained

object…glasses　of　fifteen　inches　aperture。



The　pernicious　impost　upon　flint　glass　having　at　length　been

removed　by　the　English　Government；　an　opportunity　was　afforded　to

our　native　opticians　to　recover　the　supremacy　which　they　had　so

long　lost。　　It　is　to　Thomas　Cooke；　more　than　to　any　other　person；

that　we　owe　the　recovery　of　this　manufacture。　　Mr。　Lockyer；

writing　in　1878；　says：　〃The　two　largest　and　most　perfectly

mounted　refractors　on　the　German　form　at　present　in　existence　are

those　at　Gateshead　and　Washington；　U。S。　　The　former　belongs　to

Mr。　Newall；　a　gentleman　who；　connected　with　those　who　were　among

the　first　to　recognise　the　genius　of　our　great　English　optician；

Cooke；　did　not　hesitate　to　risk　thousands　of　pounds　in　one　great

experiment；　the　success　of　which　will　have　a　most　important

bearing　upon　the　astronomy　of　the　future。〃＇7＇



The　progress　which　Mr。　Cooke　made　in　his　enterprise　was　slow　but

steady。　　Shortly　after　he　began　business　as　an　optician；　he

became　dissatisfied　with　the　method　of　hand…polishing；　and　made

arrangements　to　polish　the　object…glasses　by　machinery　worked　by

steam　power。　　By　this　means　he　secured　perfect　accuracy　of

figure。　　He　was　also　able　to　turn　out　a　large　quantity　of

glasses；　so　as　to　furnish　astronomers　in　all　parts　of　the　world

with　telescopes　of　admirable　defining　power；　at　a　comparatively

moderate　price。　　In　all　his　works　he　endeavoured　to　introduce

simplicity。　　He　left　his　mark　on　nearly　every　astronomical

instrument。　　He　found　the　equatorial　comparatively　clumsy；　he

left　it　nearly　perfect。　　His　beautiful　〃dividing　machine；〃　for

marking　divisions　on　the　circles；　four　feet　in　diameter　and

altogether　self…actingwhich　divides　to　five　minutes　and　reads

off　to　five　seconds　is　not　the　least　of　his　triumphs。



The　following　are　some　of　his　more　important　achromatic

telescopes。　　In　1850；　when　he　had　been　fourteen　years　in

business；　he　furnished　his　earliest　patron；　Professor　Phillips；

with　an　equatorial　telescope　of　6　1/4　inches　aperture。　　His

second　（of　6　1/8）　was　supplied　two　years　later；　to　James

Wigglesworth　of　Wakefield。　　William　Gray；　Solicitor；　of　York；　one

of　his　earliest　friends；　bought　a　6　1/2…inch　telescope　in　1853。　

In　the　following　year；　Professor　Pritchard　of　Oxford　was　supplied

with　a　6　1/2…inch。　　The　other　important　instruments　were　as

follows：　in　1854；　Dr。　Fisher；　Liverpool；　6　inches；　in　1855；　H。　L。

Patterson；　Gateshead；　7　1/4　inches；　in　1858；　J。　G。　Barclay；

Layton；　Essex；　7　1/4　inches；　in　1857；　Isaac　Fletcher；

Cockermouth；　9　1/4　inches；　in　l858；　Sir　W。　Keith　Murray；

Ochtertyre；　Crieff；　9　inches；　in　1859；　Captain　Jacob；　9　inches；　

in　1860；　James　Nasmyth；　Penshurst；　8　inches；　in　1861；　another

telescope　to　J。　G。　Barclay；　10　inches；　in　1864；　the　Rev。　W。　R。　

Dawes；　Haddenham；　Berks；　8　inches；　and　in　1867；　Edward　Crossley；

Bermerside；　Halifax；　9　3/8　inches。



In　1855　Mr。　Cooke　obtained　a　silver　medal　at　the　first　Paris

Exhibition　for　a　six…inch　equatorial　telescope。＇8＇　　This　was　the

highest　prize　awarded。　　A　few　years　later　he　was　invited　to

Osborne　by　the　late　Prince　Albert；　to　discuss　with　his　Royal

Highness　the　particulars　of　an　equatorial　mounting　with　a　clock

movement；　for　which　he　subsequently　received　the　order。　　On　its

completion　he　superintended　the　erection　of　the　telescope；　and

had　the　honour　of　directing　it　to　several　of　the　celestial

objects　for　the　Queen　and　the　Princess　Alice；　and　answered　their

many　interesting　questions　as　to　the　stars　and　planets　within

sight。



Mr。　Cooke　was　put　to　his　mettle　towards　the　close　of　his　life。　　A

contest　had　long　prevailed　among　telescope　makers　as　to　who

should　turn　out　the　largest　refracting　instrument。　　The　two

telescopes　of　fifteen　inches　aperture；　prepared　by　Merz　and

Mahler；　of　Munich；　were　the　largest　then　in　existence。　　Their

size　was　thought　quite　extraordinary。　　But　in　1846；　Mr。　Alvan

Clark；　of　Cambridgeport；　Massachusetts；　U。S。；　spent　his　leisure

hour's　in　constructing　small　telescopes。＇9＇　He　was　not　an

optician；　nor　a　mathematician；　but　a　portrait　painter。　　He

possessed；　however；　enough　knowledge　of　optics　and　of　mechanics；

to　enable　him　to　make　and　judge　a　telescope。　　He　spent　some　ten

years　in　grinding　lenses；　and　was　at　length　enabled　to　produce

objectives　equal　in　quality　to　any　ever　made。



In　1853；　the　Rev。　W。　E。　Dawesone　of　Mr。　Cooke's　customers　

purchased　an　object…glass　from　Mr。　Clark。　　It　was　so　satisfactory

that　he　ordered　several　others；　and　finally　an　entire　telescope。　

The　American　artist　then　began　to　be　appreciated　in　his　own

country。　　In　1860　he　received　an　order　for　a　refractor　of

eighteen　inches　aperture；　three　inches　greater　than　the　largest

which　had　up　to　that　time　been　made。　　This　telescope　was　intended

for　the　Observatory　of　Mississippi；　but　the　Civil　War　prevented

its　being　removed　to　the　South；　and　the　telescope　was　sold　to　the

Astronomical　Society　of　Chicago　and　mounted　in　the　Observatory　of

that　city。



And　now　comes　in　the　rivalry　of　Mr。　Cooke　of　York；　or　rather　of

his　patron；　Mr。　Newall　of　Gateshead。　　At　the　Great　Exhibition　of

London；　in　1862；　two　large　circular　blocks　of　glass；　about　two

inches　thick　and　twenty…six　inches　in　diameter；　were　shown　by　the

manufacturers；　Messrs。　Chance　of　Birmingham。　　These　discs　were

found　to　be　of　perfect　quality；　and　suitable　for　object…glasses

of　the　best　kind。　　At　the　close　of　the　Exhibition；　they　were

purchased　by　Mr。　Newall；　and　transferred　to　the　workshops　of

Messrs。　Cooke　and　Sons　at　York。　　To　grind　and　polish　and　mount

these　discs　was　found　a　work　of　great　labour　and　difficulty。　　Mr。

Lockyer　says；　〃such　an　achievement　marks　an　epoch　in　telescopic

astronomy；　and　the　skill　of　Mr。　Cooke　and　the　munificence　of　Mr。

Newall　will　long　be　remembered。〃



When　finished；　the　object…glass　had　an　aperture　of　nearly

twenty…five　inches；　and　was　of　much　greater　power　than　the

eighteen…inch　Chicago　instrument。　　The　length　of　the　tube　was

about　thirty…two　feet。　　The　cast…iron　pillar　supporting　the　whole

was　nineteen　feet　in　height　from　the　ground；　and　the　weight　of

the　whole　instrument　was　about　six　tons。　　In　preparing　this

telescope；　nearly　everything；　from　its　extraordinary　size；　had　to

be　specially　arranged。＇10＇　　The　great　anxiety　involved　in　these

arrangements；　and　the　constant　study　and　application　told　heavily

upon　Mr。　Cooke；　and　though　the　instrument　wanted　only　a　few

touches　to　make　it　complete；　his　health　broke　down；　and　he　died

on　the　l9th　of　October；　1868；　at　the　comparatively　early　age　of

sixty…two。



Mr。　Cooke's　death　was　felt；　in　a　measure；　to　be　a　national　loss。　

His　science　and　skill　had　restored　to　England　the　prominent

position　she　had　held　in　the　time　of　Dollond；　and；　had　he　lived；

even　more　might　have　been　expected　from　him。　　We　believe　that　the

Gold　Medal　and　Fellowship　of　the　Royal　Society　were　waiting　for

him；　but；　as　one　of　his　friends　said　to　his　widow；　〃neither　worth

nor　talent　avails　when　the　great　ordeal　is　presented　to　us。〃　　In

a　letter　from　Professor　Pritchard；　he　said：　〃Your　husband　has

left　his　mark　upon　his　age。　　No　optician　of　modern　times　has

gained　a　higher　reputation；　and　I　for　one　do　not　hesitate　to　call

h