forty centuries of ink-第59章

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does　not　acquire　momentum　enough　to　overpower

him。　When　the　cask　has　been　thus　guided　safely　to

the　bottom；　the　man　carries　the　sledge　up　hill　upon

his　shoulders；　and　prepares　for　another　descent。



Up　to　about　the　middle　of　the　eighteenth　century　the

mine　was　opened　only　once　in　seven　years；　the　quantity

taken　out　at　each　time　of　opening　being　such　as　was

deemed　sufficient　to　serve　the　market　for　seven　years；

but　when；　at　a　later　period；　it　was　found　that　the

demand　was　increasing　and　the　supply　decreasing；　it

was　deemed　necessary　to　work　the　mine　six　or　seven

weeks　every　year。　During　the　time　of　working；　the

mine　is　guarded　night　and　day；　and　when　a　quantity

sufficient　for　one　year's　consumption　has　been　taken

out；　the　mine　is　secured　until　the　following　year。

Several　hundred　cartloads　of　rubbish　are　wheeled　into

the　mine；　so　as　to　block　up　the　entrance　completely；

and　this　rubbish　acts　as　a　dam　to　prevent　the　springs

and　land　waters　from　flowing　out；　so　that　the　mine

gradually　becomes　flooded。



When　the　Year's　mining　is　concluded；　the　barrels

of　black…lead　are　brought　to　market；　and　the　mode

of　effecting　the　sales　was　described　by　Dr。　Faraday

some　years　ago　to　be　as　follows：　A　market　is　held　on

the　first　Monday　of　every　month　at　a　house　in　London；

where　the　buyers；　who　are　generally　only　seven

or　eight　in　number；　examine　each　piece　with　a　sharp

instrument　to　ascertain　its　hardness；　those　which　are

too　soft　being　rejected。　The　person　who　has　the

first　choice　pays　45s。　per　pound；　the　others　30s。

But；　as　there　is　no　addition　made　to　the　first　quantity

in　the　market；　the　residual　portions　are　examined

over　and　over　again　until　they　are　exhausted。　At

one　time　the　annual　sale　was　said　to　amount　to　the

value　of　L40；000　per　annum；　but　it　has　been　greatly

reduced　since。



A　mode　of　applying　manufacturing　processes　to

the　preparation　of　black…lead　is　described　by　Dr。

Ure　as　being　adopted　in　Paris。　The　mineral；　being

reduced　to　a　fine　powder；　is　mixed　with　very　pure

powdered　clay；　and　the　two　are　calcined　in　a　crucible

at　a　white　heat；　the　proportion　of　clay　employed

is　greater　as　the　pencil　is　required　to　be　harder；

the　average　being　equal　parts　of　both。　The

ingredients　are　ground　with　a　muller　on　a　porphyry　slab　and

then　made　into　balls；　which　are　preserved　in　a　moist

atmosphere　in　the　form　of　paste。　The　paste　is　pressed

into　grooves　cut　in　a　smooth　board；　and　another　board；

previously　greased；　is　pressed　down　upon　it。　When

the　paste　has　had　time　to　dry；　the　mould　or　grooved

board　is　put　into　a　moderately　heated　oven；　by　which

the　paste；　now　in　the　form　of　square　pencils；　shrinks

sufficiently　to　fall　out　of　the　grooves。　In　order　to

give　solidity　to　the　pencils　they　are　set　upright　in　a

crucible　and　surrounded　with　pounded　charcoal；　fine

sand；　or　sifted　ashes；　the　crucible；　being　covered；　is

exposed　to　a　degree　of　heat　proportionate　to　the

hardness　required　in　the　pencils；　the　harder　pencils

requiring　the　higher　degree　of　heat。　Some　of　the

pencils　are　shaped　in　a　curious　manner：　models　of　the

pencils；　made　of　iron；　are　stuck　upright　upon　an　iron

tray；　having　edges　raised　as　high　as　the　intended

length　of　the　pencils；　and　a　metallic　alloy；　made　of

tin；　lead；　antimony　and　bismuth　is　poured　into　the

sheet…iron　tray。　When　the　alloy　has　cooled；　it　is　inverted

and　shaken　off　from　the　model…rods；　so　as　to

form　a　mass　of　metal　perforated　throughout　with

tubular　cavities　corresponding　in　size　with　the　intended

pencil　pieces；　the　pencil　paste　is　introduced

by　pressure　into　these　cavities；　and　when　nearly　dry

the　pieces　shrink　sufficiently　to　be　easily　removed

from　the　cavities。



The　pencils　just　described　are　alike　throughout　all

their　thickness；　but　in　the　majority　of　English　pencils

there　is　a　wooden　holder　to　contain　a　narrow

filament　of　black　lead　running　down　the　middle。　So

long　ago　as　the　year　1618　this　mode　was　adopted；　for

Sir　John　Pettus；　who　was　deputy　governor　of　the

Borrowdale　mine　under　Charles　II；　in　his　〃Fleta

Minor；〃　while；　speaking　of　black…lead　says；　that　〃Of

late　it　is　curiously　formed　into　cases　of　deal　or　cedar

and　so　sold　as　dry　pencils；　something　more　useful　than

pen　and　ink。〃　In　a　general　way　modern　black…lead

pencils；　are　made　by　sawing　cedar　first　into　long

planks；　and　then　into　smaller　rods；　grooves　are　cut

out　by　means　of　a　cutting　machine　moved　by　a　fly…

wheel　to　such　a　depth　as　will　receive　a　small　layer　of

black…lead；　the　pieces　of　the　mineral　are　cut　into　thin

slabs　and　then　into　rods　the　same　size　as　the　grooves；

into　which　they　are　inserted；　the　two　halves　of　the

case　are　then　glued　together；　and　the　whole　is　turned

into　a　cylindrical　form　by　means　of　a　guage。



The　kind　of　pencil　called　〃crayon〃　is　a　mixture

of　some　kind　of　earth　with　a　coloring　substance。

The　earth　employed　is　sometimes　chalk；　and　at　other

times　pipe…clay；　gypsum；　starch…flour；　or　ochre。　The

coloring　substance　is　yellow　ochre；　mineral　yellow；

chrome；　red　chalk；　vermilion；　indigoindeed；　any　of

the　usual　dry　colors；　according　to　the　tint　required。

Besides　the　earth　and　the　color；　there　is　a　gummy　liquid

required　to　combine　them　together；　gum　arabic；　gum

tragacanth；　and　in　some　cases　oil；　wax；　or　suet；　are

used　as　the　third　ingredient。　The　crayons　here　alluded

to　are　employed　rather　for　drawing　than　for　writing；

but　they　obviously　belong　to　the　class　of　pencils　in

their　mode　of　action。



The　ancients　drew　lines　and　letters　with　wooden

styles；　and　afterward　an　alloy　of　lead　and　tin　was

used。　Pliny　refers　to　the　use　of　lead　for　ruling　lines

on　papyrus。　La　Moine　cites　a　document　of　1387

ruled　with　graphite。　Slips　of　graphite　in　wooden

sticks　（pencils）　are　mentioned　by　Gesner；　of　Zurich；　in

1565；　he　credits　England　with　the　production。　They

are　doubtless　the　product　of　the　Borrowdale　mine；

then　lately　discovered。　In　the　early　part　of　the　seventeenth

century　black…lead　pencils　are　distinctly　described

by　several　writers。　They　are　noticed　by

Ambrosinus；　1648；　spoken　of　by　Pettus；　in　1683；　as

inclosed　in　fir　or　cedar。



Red　and　black　chalk　pencils　were　used　in　Germany

in　1450；　in　fact；　fragments　of　chalk；　charcoal；　and

shaped　sticks　of　colored　minerals　had　been　in　use

since　times　previous　to　all　historic　mention。



When　Cortez　landed　in　Mexico；　in　1520；　he　found

the　Aztecs　using　graphite　crayons；　which　were　probably

made　from　a　mineral　found　in　Sonora。



The　firm　of　A。　W。　Faber　are　the　largest　manufacturers

of　lead　pencils　in　the　world。　They　have　compiled

a　history　of　this　implement　of　handwriting　which

they　have　permitted　me　to　use　in　the　story　which

follows。



The　lead　pencil　is　an　invention　of　modern　times；

and　its　introduction　may　deservedly　be　ranked　with

the　large　number　of　technical　innovations　in　which

more　especially　the　last　three　centuries　have　been　so

rich；　nor　can　it　be　denied　that　pencils　have　played

an　important　part　in　the　diffusion　of　arts　and　sciences

and　in　facilitating　study　and　intellectual　intercourse。



To　the　classic　ages　and　their　art　the　pencil；　and　in

general　every　application　of　lead　as　a　writing　material；

was　entirely　unknown；　and　it　was　not　till　the　advent

of　the　middle　ages　that　it　began　to　be　used　for　this

purpose。　This　lead；　i。　e。　metallic　lead；　however；　was

in　no　way　equivalent　to　the　graphite　or　black…lead　of

our　pencils；　which　are　only　honored　with　the　prefix

of　〃lead；〃　owing　to　the　leaden　color　of　the　writing

done　with　them。



Moreover；　in　those　days；　lead　was　used　exclusively

for　ruling　and　in　no　way　for　writing　or　drawing；　it

was　employed　in　the　form　of　round；　sharp…edged　discs；

similar　to　those　which；　it　is　said；　were　already　used

for　the　same　purpose　in　ancient　classic　times。　It　is

only　with　the　development　and　growth　of　modern

painting　that　traces　of　pencil…like　drawings　first　begin

to　be　met。　At　so　early　a　period　even　as　the　fourteenth