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forty centuries of ink-第52章

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and a saw extends the aperture along the pen itself。

The inside edges of the slit are smoothed and polished

by the emery wheel; burnishing and hammering

produce the proper degree of elasticity。〃



It is asserted that more steel is used in the manufacture

of pens than in all the swords and guns in the

world。 This fact partly verifies the old saying; 〃The

pen is mightier than the sword。〃



 〃Three things bear mighty sway with men;

 The Sword; the Sceptre; and the Pen;

 Who can the least of these command;

 In the first rank of Fame will stand。〃







CHAPTER XXVII。



SUBSTITUTES FOR INK UTENSILS (〃LEAD〃 AND OTHER

PENCILS)。



〃BLACK…LEAD〃 PENCILS AN EXCELLENT PEN SUBSTITUTE

UNDER CERTAIN CONDITIONSITS COMPOSITION

〃BLACK…LEAD〃 CONTAINS NO LEAD; HENCE

THE NAME IS MISAPPLIEDTHE DISCOVERY OF ITS

PRINCIPAL SOURCE OF SUPPLY AN ACCIDENTA

DESCRIPTION OF HOW IT IS MINEDTREATMENT

BEFORE BEING INTRODUCED INTO THE GROOVED

WOODUSE OF RED AND BLACK CHALK PENCILS

IN GERMANY; 1450THEIR USE IN MEXICO IN EARLY

TIMESWHO MANUFACTURES LEAD PENCILSEMPLOYMENT

OF THE COMPOSITION OF LEAD AND TIN

IN MEDIAEVAL TIMESBAVARIAN GOVERNMENT IN

1816 A MANUFACTURER OF LEAD PENCILS。



THE black…lead pencil; under many circumstances;

is a very useful substitute for the pen; in that it

requires no liquid ink for marking the characters on

paper or other materials。 The peculiar substance

which fills the central channel of the stick of cedar

has the property of marking when it touches paper;

and; as the marks thus made are susceptible to easy

removal; a pencil of this kind is available for purposes

which would not be answered by the use of pen and ink。



The substance misnamed 〃black…lead〃 contains NO

LEAD and is a carburet of iron; being composed of

carbon and iron。 It generally occurs in Mountain districts;

in small kidney…shaped pieces; varying in size

from that of a pea upwards; which are interspersed

among various strata; and is met with in different

parts of the world。



Its principal source of supply until about 1845;

when it became exhausted; was the Borrowdale mine

in Cumberland; England; which was discovered in

1564。 About 1852 a number of mines were opened

containing this substance in Siberia and from which

place the best products are now obtained。



The accidental discovery of this mineral at Borrowdale

was during the reign of Queen Elizabeth who

made many inquiries about it。 The name of this

mineral was locally known as wad (graphite)。 So

valuable was it regarded that it commanded a very

high price; and this price acted as in inducement to

the workmen and others to pilfer pieces from the

mine。 For a number of years scenes of great commotion

took place; arising out of these depredations; and

the result was that the proprietors adopted such

stringent rules that hardly anything was known of

the internal economy of the mine till about sixty

years ago; when Mr。 Parkes gave a description of it;

from which I may condense a few particulars。



The mine is in the midst of a mountain about two

thousand feet high; which rises at in angle of about

45 degrees; and; as that part of the mine which has been

worked during the last century is near the middle

of the mountain; the present entrance is about a

thousand feet from the summit。 The opening by

which the workmen enter descends by a flight of

steps; and in order to guard the treasure within; the

proprietors have erected a strong brick building of

four rooms; one of which is immediately over the

entrance into the mine。 This entrance is secured by a

trap…door; and the room connected with it serves as a

dressing…room for the men when they enter and leave

the mine。 The men work in gangs; which relieve

each other every six hours; and when the hour of

relief comes; a steward or foreman attends the dressing…

room to see the men change their dresses as they

come up one by one out of the mine。 The clothes

are examined by the steward to see that no black…lead

is concealed in them; and when the men have dressed

they leave the mine; making room for another gang;

who change their clothes; enter the mine; and are fastened

in for six hours。 In one of the four rooms of which

the house consists there is a table; at which men are

employed in sorting and dressing the mineral。 This is

necessary; because it is usually divided into two qualities;

the finest of which have generally pieces of iron…

ore or other impurity attached to them; which must

be dressed off。 These men; who are strictly watched

while at work; put the dressed black…lead into casks

holding about one hundred…weight each; in which state

it leaves the mine。 The casks are conveyed down

the side of the mountain in a curious manner。 Each

cask is fixed upon a light sledge with two wheels;

and a man; who is well used to the precipitous path;

walks down in front of the sledge; taking care that it

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 g
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