On the Economy of Machinery and Manufactures
by
Charles Babbage
Part 2 out of 6
saws, having a very thin blade, have been employed for such
purposes. In order to economize still further the more valuable
woods, Mr Brunel contrived a machine which, by a system of
blades, cut off the veneer in a continuous shaving, thus
rendering the whole of the piece of timber available.
78. The rapid improvements which have taken place in the
printing press during the last twenty years, afford another
instance of saving in the materials consumed, which has been well
ascertained by measurement, and is interesting from its
connection with literature. In the old method of inking type, by
large hemispherical balls stuffed and covered with leather, the
printer, after taking a small portion of ink from the ink-block,
was continually rolling the balls in various directions against
each other, in order that a thin layer of ink might be uniformly
spread over their surface. This he again transferred to the type
by a kind of rolling action. In such a process, even admitting
considerable skill in the operator, it could not fail to happen
that a large quantity of ink should get near the edges of the
balls, which, not being transferred to the type, became hard and
useless, and was taken off in the form of a thick black crust.
Another inconvenience also arose--the quantity of ink spread on
the block not being regulated by measure, and the number and
direction of the transits of the inking-balls over each other
depending on the will of the operator, and being consequently
irregular, it was impossible to place on the type a uniform layer
of ink, of the quantity exactly sufficient for the impression.
The introduction of cylindrical rollers of an elastic substance,
formed by the mixture of glue and treacle, superseded the
inking-balls, and produced considerable saving in the consumption
of ink: but the most perfect economy was only to be produced by
mechanism. When printing-presses, moved by the power of steam,
were introduced, the action of these rollers was found to be well
adapted to their performance; and a reservoir of ink was formed,
from which a roller regularly abstracted a small quantity at each
impression. From three to five other rollers spread this portion
uniformly over a slab (by most ingenious contrivances varied in
almost each kind of press), and another travelling roller, having
fed itself on the slab, passed and repassed over the type just
before it gave the impression to the paper.
In order to shew that this plan of inking puts the proper
quantity of ink upon the type, we must prove, first--that the
quantity is not too little: this would soon have been discovered
from the complaints of the public and the booksellers; and,
secondly that it is not too great. This latter point was
satisfactorily established by an experiment. A few hours after
one side of a sheet of paper has been printed upon, the ink is
sufficiently dry to allow it to receive the impression upon the
other; and, as considerable pressure is made use of, the tympan
on which the side first printed is laid, is guarded from soiling
it by a sheet of paper called the set-off sheet. This paper
receives, in succession, every sheet of the work to be printed,
acquiring from them more or less of the ink, according to their
dryness, or the quantity upon them. It was necessary in the
former process, after about one hundred impressions, to change
this set-off sheet, which then became too much soiled for further
use. In the new method of printing by machinery, no such sheet is
used, but a blanket is employed as its substitute; this does not
require changing above once in five thousand impressions, and
instances have occurred of its remaining sufficiently clean for
twenty thousand. Here, then, is a proof that the quantity of
superfluous ink put upon the paper in machine-printing is so
small, that, if multiplied by five thousand, and in some
instances even by twenty thousand, it is only sufficient to
render useless a single piece of clean cloth.(1*) The following
were the results of an accurate experiment upon the effect of the
process just described, made at one of the largest printing
establishments in the metropolis.(2*) Two hundred reams of paper
were printed off, the old method of inking with balls being
employed; two hundred reams of the same paper, and for the same
book, were then printed off in the presses which inked their own
type. The consumption of ink by the machine was to that by the
balls as four to nine, or rather less than one-half.
NOTES:
1. In the very best kind of printing, it is necessary, in the old
method, to change the set-off sheet once in twelve times. In
printing the same kind of work by machinery, the blanket is
changed once in 2000.
2. This experiment was made at the establishment of Mr Clowes, in
Stamford Street.
Chapter 10
Of the Identity of the Work When It is of the Same Kind, and its
Accuracy when of Different Kinds
79. Nothing is more remarkable, and yet less unexpected, than
the perfect identity of things manufactured by the same tool. If
the top of a circular box is to be made to fit over the lower
part, it may be done in the lathe by gradually advancing the tool
of the sliding-rest; the proper degree of tightness between the
box and its lid being found by trial. After this adjustment, if a
thousand boxes are made, no additional care is required; the tool
is always carried up to the stop, and each box will be equally
adapted to every lid. The same identity pervades all the arts of
printing; the impressions from the same block, or the same
copperplate, have a similarity which no labour could produce by
hand. The minutest traces are transferred to all the impressions,
and no omission can arise from the inattention or unskilfulness
of the operator. The steel punch, with which the cardwadding for
a fowling-piece is cut, if it once perform its office with
accuracy, constantly reproduces the same exact circle.
80. The accuracy with which machinery executes its work is,
perhaps, one of its most important advantages: it may, however,
be contended, that a considerable portion of this advantage may
be resolved into saving of time; for it generally happens, that
any improvement in tools increases the quantity of work done in a
given time. Without tools, that is, by the mere efforts of the
human hand, there are, undoubtedly, multitudes of things which it
would be impossible to make. Add to the human hand the rudest
cutting instrument, and its powers are enlarged: the fabrication
of many things then becomes easy, and that of others possible
with great labour. Add the saw to the knife or the hatchet, and
other works become possible, and a new course of difficult
operations is brought into view, whilst many of the former are
rendered easy. This observation is applicable even to the most
perfect tools or machines. It would be possible for a very
skilful workman, with files and polishing substances, to form a
cylinder out of a piece of steel; but the time which this would
require would be so considerable, and the number of failures
would probably be so great, that for all practical purposes such
a mode of producing a steel cylinder might be said to be
impossible. The same process by the aid of the lathe and the
sliding-rest is the everyday employment of hundreds of workmen.
81. Of all the operations of mechanical art, that of turning
is the most perfect. If two surfaces are worked against each
other, whatever may have been their figure at the commencement,
there exists a tendency in them both to become portions of
spheres. Either of them may become convex, and the other concave,
with various degrees of curvature. A plane surface is the line of
separation between convexity and concavity, and is most difficult
to hit; it is more easy to make a good circle than to produce a
straight line. A similar difficulty takes place in figuring
specula for telescopes; the parabola is the surface which
separates the hyperbolic from the elliptic figure, and is the
most difficult to form. If a spindle, not cylindrical at its end,
be pressed into a hole not circular, and kept constantly turning,
there is a tendency in these two bodies so situated to become
conical, or to have circular sections. If a triangular-pointed
piece of iron be worked round in a circular hole the edges will
gradually wear, and it will become conical. These facts, if
they do not explain, at least illustrate the principles on
which the excellence of work formed in the lathe depends.
Chapter 11
Of Copying
82. The two last-mentioned sources of excellence in the work
produced by machinery depend on a principle which pervades a very
large portion of all manufactures, and is one upon which the
cheapness of the articles produced seems greatly to depend. The
principle alluded to is that of copying, taken in its most
extensive sense. Almost unlimited pains are, in some instances,
bestowed on the original, from which a series of copies is to be
produced; and the larger the number of these copies, the more
care and pains can the manufacturer afford to lavish upon the
original. It may thus happen, that the instrument or tool
actually producing the work, shall cost five or even ten thousand
times the price of each individual specimen of its power.
As the system of copying is of so much importance, and of
such extensive use in the arts, it will be convenient to classify
a considerable number of those processes in which it is employed.
The following enumeration however is not offered as a complete
list; and the explanations are restricted to the shortest
possible detail which is consistent with a due regard to making
the subject intelligible.
Operations of copying are effected under the following
circumstances:
by printing from cavities by stamping
by printing from surface by punching
by casting with elongation
by moulding with altered dimensions
Of printing from cavities
83. The art of printing, in all its numerous departments, is
essentially an art of copying. Under its two great divisions,
printing from hollow lines, as in copperplate, and printing from
surface, as in block printing, are comprised numerous arts.
84. Copperplate printing. In this instance, the copies are
made by transferring to paper, by means of pressure, a thick ink,
from the hollows and lines cut in the copper. An artist will
sometimes exhaust the labour of one or two years upon engraving a
plate, which will not, in some cases furnish above five hundred
copies in a state of perfection.
85. Engravings on steel. This art is like that of engraving
on copper, except that the number of copies is far less limited.
A bank-note engraved as a copperplate, will not give above three
thousand impressions without a sensible deterioration. Two
impressions of a bank-note engraved on steel were examined by one
of our most eminent artists,(1*) who found it difficult to
pronounce with any confidence, which was the earliest impression.
One of these was a proof from amongst the first thousand, the
other was taken after between seventy and eighty thousand had
been printed off.
86. Music printing. Music is usually printed from pewter
plates, on which the characters have been impressed by steel
punches. The metal being much softer than copper, is liable to
scratches, which detain a small portion of the ink. This is the
reason of the dirty appearance of printed music. A new process
has recently been invented by Mr Cowper, by which this
inconvenience will be avoided. The improved method, which give
sharpness to the characters, is still an art of copying; but it
is effected by surface printing, nearly in the same manner as
calico-printing from blocks, to be described hereafter, 96. The
method of printing music from pewter plates, although by far the
most frequently made use of, is not the only one employed, for
music is occasionally printed from stone. Sometimes also it is
printed with moveable type; and occasionally the musical
characters are printed on the paper, and the lines printed
afterwards. Specimens of both these latter modes of
music-printing may be seen in the splendid collection of
impressions from the types of the press of Bodoni at Parma: but
notwithstanding the great care bestowed on the execution of that
work, the perpetual interruption of continuity in the lines,
arising from the use of moveable types, when the characters and
lines are printed at the same time, is apparent.
87. Calico printing from cylinders. Many of the patterns on
printed calicos are copies by printing from copper cylinders
about four or five inches in diameter, on which the desired
pattern has been previously engraved. One portion of the
cylinders is exposed to the ink, whilst an elastic scraper of
very thin steel, by being pressed forcibly against another part,
removes all superfluous ink from the surface previously to its
reaching the cloth. A piece of calico twenty-eight yards in
length rolls through this press, and is printed in four or five
minutes.
88. Printing from perforated sheets of metal, or stencilling.
Very thin brass is sometimes perforated in the form of letters,
usually those of a name; this is placed on any substance which it
is required to mark, and a brush dipped in some paint is passed
over the brass. Those parts which are cut away admit the paint.
and thus a copy of the name appears on the substance below. This
method, which affords rather a coarse copy, is sometimes used for
paper with which rooms are covered, and more especially for the
borders. If a portion be required to match an old pattern, this
is, perhaps the most economical way of producing it.
89. Coloured impressions of leaves upon paper may be made by
a kind of surface printing. Such leaves are chosen as have
considerable inequalities: the elevated parts of these are
covered, by means of an inking ball, with a mixture of some
pigment ground up in linseed oil; the leaf is then placed between
two sheets of paper, and being gently pressed, the impression
from the elevated parts on each side appear on the corresponding
sheets of paper.
90. The beautiful red cotton handkerchiefs dyed at Glasgow
have their pattern given to them by a process similar to
stencilling, except that instead of printing from a pattern, the
reverse operation that of discharging a part of the colour from a
cloth already dyed--is performed. A number of handkerchiefs are
pressed with very great force between two plates of metal, which
are similarly perforated with round or lozenge-shaped holes,
according to the intended pattern. The upper plate of metal is
surrounded by a rim, and a fluid which has the property of
discharging the red dye is poured upon that plate. This liquid
passes through the holes in the metal, and also through the
calico; but, owing to the great pressure opposite all the parts
of the plates not cut away, it does not spread itself beyond the
pattern. After this, the handkerchiefs are washed, and the
pattern of each is a copy of the perforations in the metal-plate
used in the process.
Another mode by which a pattern is formed by discharging
colour from a previously dyed cloth, is to print on it a pattern
with paste; then, passing it into the dying-vat, it comes out
dyed of one uniform colour But the paste has protected the fibres
of the cotton from the action of the dye or mordant; and when the
cloth so dyed is well washed, the paste is dissolved, and leaves
uncoloured all those parts of the cloth to which it was applied.
Printing from surface
91. This second department of printing is of more frequent
application in the arts than that which has just been considered.
92. Printing from wooden blocks. A block of box wood is, in
this instance, the substance out of which the pattern is formed:
the design being sketched upon it, the workman cuts away with
sharp tools every part except the lines to be represented in the
impression. This is exactly the reverse of the process of
engraving on copper, in which every line to be represented is cut
away. The ink, instead of filling the cavities cut in the wood,
is spread upon the surface which remains, and is thence
transferred to the paper.
93. Printing from moveable types. This is the most important
in its influence of all the arts of copying. It possesses a
singular peculiarity, in the immense subdivision of the parts
that form the pattern. After that pattern has furnished thousands
of copies, the same individual elements may be arranged again and
again in other forms, and thus supply multitudes of originals,
from each of which thousands of their copied impressions may
flow. It also possesses this advantage, that woodcuts may be used
along with the letterpress, and impressions taken from both at
the same operation.
94. Printing from stereotype. This mode of producing copies
is very similar to the preceding. There are two modes by which
stereotype plates are produced. In that most generally adopted a
mould is taken in plaster from the moveable types, and in this
the stereotype plate is cast. Another method has been employed in
France: instead of composing the work in moveable type, it was
set up in moveable copper matrices; each matrix being in fact a
piece of copper of the same size as the type, and having the
impression of the letter sunk into its surface instead of
projecting in relief. A stereotype plate may, it is evident, be
obtained at once from this arrangement of matrices. The objection
to the plan is the great expense of keeping so large a collection
of matrices.
As the original composition does not readily admit of change,
stereotype plates can only be applied with advantage to cases
where an extraordinary number of copies are demanded, or where
the work consists of figures, and it is of great importance to
ensure accuracy. Trifling alterations may, however, be made in it
from time to time; and thus mathematical tables may, by the
gradual extirpation of error, at last become perfect. This mode
of producing copies possesses, in common with that by moveable
types, the advantage of admitting the use of woodcuts: the copy
of the woodcut in the stereotype plate being equally perfect.
with that of the moveable type. This union is of considerable
importance, and cannot be accomplished with engravings on copper.
95. Lettering books. The gilt letters on the backs of books
are formed by placing a piece of gold leaf upon the leather, and
pressing upon it brass letters previously heated: these cause the
gold immediately under them to adhere to the leather, whilst the
rest of the metal is easily brushed away. When a great number of
copies of the same volume are to be lettered, it is found to be
cheaper to have a brass pattern cut with the whole of the proper
title: this is placed in a press, and being kept hot, the covers,
each having a small bit of leaf-gold placed in the proper
position, are successively brought under the brass, and stamped.
The lettering at the back of the volume in the reader's hand was
executed in this manner.
96. Calico printing from blocks. This is a mode of copying,
by surface printing, from the ends of small pieces of copper
wire, of various forms, fixed into a block of wood. They are all
of one uniform height, about the eighth part of an inch above the
surface of the wood, and are arranged by the maker into any
required pattern. If the block be placed upon a piece of fine
woollen cloth, on which ink of any colour has been uniformly
spread, the projecting copper wires receive a portion, which they
give up when applied to the calico to be printed. By the former
method of printing on calico, only one colour could be used; but
by this plan, after the flower of a rose, for example, has been
printed with one set of blocks, the leaves may be printed of
another colour by a different set.
97. Printing oilcloth. After the canvas, which forms the
basis of oilcloth, has been covered with paint of one uniform
tint, the remainder of the processes which it passes through, are
a series of copyings by surface printing, from patterns formed
upon wooden blocks very similar to those employed by the calico
printer. Each colour requiring a distinct set of blocks, those
oilcloths with the greatest variety of colours are most
expensive.
There are several other varieties of printing which we shall
briefly notice as arts of copying; which, although not strictly
surface printing, yet are more allied to it than that from
copperplates.
98. Letter copying. In one of the modes of performing this
process, a sheet of very thin paper is damped, and placed upon
the writing to be copied. The two papers are then passed through
a rolling press, and a portion of the ink from one paper is
transferred to the other. The writing is, of course, reversed by
this process; but the paper to which it is transferred being
thin, the characters are seen through it on the other side, in
their proper position. Another common mode of copying letters is
by placing a sheet of paper covered on both sides with a
substance prepared from lamp-black, between a sheet of thin paper
and the paper on which the letter to be despatched is to be
written. If the upper or thin sheet be written upon with any hard
pointed substance, the word written with this style will be
impressed from the black paper upon both those adjoining it. The
translucency of the upper sheet, which is retained by the writer,
is in this instance necessary to render legible the writing which
is on the back of the paper. Both these arts are very limited in
their extent, the former affording two or three, the latter from
two to perhaps ten or fifteen copies at the same time.
99. Printing on china. This is an art of copying which is
carried to a very great extent. As the surfaces to which the
impression is to be conveyed are often curved, and sometimes even
fluted, the ink, or paint, is first transferred from the copper
to some flexible substance, such as paper, or an elastic compound
of glue and treacle. It is almost immediately conveyed from this
to the unbaked biscuit, to which it more readily adheres.
100. Lithographic printing. This is another mode of producing
copies in almost unlimited number. The original which supplies
the copies is a drawing made on a stone of a slightly porous
nature, the ink employed for tracing it is made of such greasy
materials that when water is poured over the stone it shall not
wet the lines of the drawing. When a roller covered with printing
ink, which is of an oily nature, is passed over the stone
previously wetted, the water prevents this ink from adhering to
the uncovered portions; whilst the ink used in the drawing is of
such a nature that the printing ink adheres to it. In this state,
if a sheet of paper be placed upon the stone, and then passed
under a press, the printing ink will be transferred to the paper,
leaving the ink used in the drawing still adhering to the stone.
101. There is one application of lithographic printing which
does not appear to have received sufficient attention, and
perhaps further experiments are necessary to bring it to
perfection. It is the reprinting of works which have just arrived
from other countries. A few years ago one of the Paris newspapers
was reprinted at Brussels as soon as it arrived by means of
lithography. Whilst the ink is yet fresh, this may easily be
accomplished: it is only necessary to place one copy of the
newspaper on a lithographic stone; and by means of great pressure
applied to it in a rolling press, a sufficient quantity of the
printing ink will be transferred to the stone. By similar means,
the other side of the newspaper may be copied on another stone,
and these stones will then furnish impressions in the usual way.
If printing from stone could be reduced to the same price per
thousand as that from moveable types, this process might be
adopted with great advantage for the supply of works for the use
of distant countries possessing the same language. For a single
copy might be printed off with transfer ink, and thus an English
work, for example, might be published in America from stone,
whilst the original, printed from moveable types, made its
appearance on the same day in England.
102. It is much to be wished that such a method were
applicable to the reprinting of facsimiles of old and scarce
books. This, however, would require the sacrifice of two copies,
since a leaf must be destroyed for each page. Such a method of
reproducing a small impression of an old work, is peculiarly
applicable to mathematical tables, the setting up of which in
type is always expensive and liable to error, but how long ink
will continue to be transferable to stone, from paper on which it
has been printed, must be determined by experiment. The
destruction of the greasy or oily portion of the ink in the
character of old books, seems to present the greatest impediment;
if one constituent only of the ink were removed by time, it might
perhaps be hoped, that chemical means would ultimately be
discovered for restoring it: but if this be unsuccessful, an
attempt might be made to discover some substance having a strong
affinity for the carbon of the ink which remains on the paper,
and very little for the paper itself.(2*)
103. Lithographic prints have occasionally been executed in
colours. In such instances a separate stone seems to have been
required for each colour, and considerable care, or very good
mechanism, must have been employed to adjust the paper to each
stone. If any two kinds of ink should be discovered mutually
inadhesive, one stone might be employed for two inks; or if the
inking-roller for the second and subsequent colours had portions
cut away corresponding to those parts of the stone inked by the
previous ones, then several colours might be printed from the
same stone: but these principles do not appear to promise much,
except for coarse subjects.
104. Register printing. It is sometimes thought necessary to
print from a wooden block, or stereotype plate, the same pattern
reversed upon the opposite side of the paper. The effect of this,
which is technically called Register printing, is to make it
appear as if the ink had penetrated through the paper, and
rendered the pattern visible on the other side. If the subject
chosen contains many fine lines, it seems at first sight
extremely difficult to effect so exact a super position of the
two patterns, on opposite sides of the same piece of paper, that
it shall be impossible to detect the slightest deviation; yet the
process is extremely simple. The block which gives the impression
is always accurately brought down to the same place by means of a
hinge; this spot is covered by a piece of thin leather stretched
over it; the block is now inked, and being brought down to its
place, gives an impression of the pattern to the leather: it is
then turned back; and being inked a second time, the paper
intended to be printed is placed upon the leather, when the block
again descending, the upper surface of the paper is printed from
the block, and its undersurface takes up the impression from the
leather. It is evident that the perfection of this mode of
printing depends in a great measure on finding some soft
substance like leather, which will take as much ink as it ought
from the block, and which will give it up most completely to
paper. Impressions thus obtained are usually fainter on the lower
side; and in order in some measure to remedy this defect, rather
more ink is put on the block at the first than at the second
impression.
Of copying by casting
105. The art of casting, by pouring substances in a fluid
state into a mould which retains them until they become solid, is
essentially an art of copying; the form of the thing produced
depending entirely upon that of the pattern from which it was
formed.
106. Of casting iron and other metals.--Patterns of wood or
metal made from drawings are the originals from which the moulds
for casting are made: so that, in fact, the casting itself is a
copy of the mould; and the mould is a copy of the pattern. In
castings of iron and metals for the coarser purposes, and, if
they are afterwards to be worked even for the finer machines,
the exact resemblance amongst the things produced, which takes
place in many of the arts to which we have alluded, is not
effected in the first instance, nor is this necessary. As the
metals shrink in cooling, the pattern is made larger than the
intended copy; and in extricating it from the sand in which it is
moulded, some little difference will occur in the size of the
cavity which it leaves. In smaller works where accuracy is more
requisite, and where few or no after operations are to be
performed, a mould of metal is employed which has been formed
with considerable care. Thus, in casting bullets, which ought to
be perfectly spherical and smooth, an iron instrument is used, in
which a cavity has been cut and carefully ground; and, in order
to obviate the contraction in cooling, a jet is left which may
supply the deficiency of metal arising from that cause, and which
is afterwards cut off. The leaden toys for children are cast in
brass moulds which open, and in which have been graved or
chiselled the figures intended to be produced.
107. A very beautiful mode of representing small branches of
the most delicate vegetable productions in bronze has been
employed by Mr Chantrey. A small strip of a fir-tree, a branch of
holly, a curled leaf of broccoli, or any other vegetable
production, is suspended by one end in a small cylinder of paper
which is placed for support within a similarly formed tin case.
The finest river silt, carefully separated from all the coarser
particles, and mixed with water, so as to have the consistency of
cream, is poured into the paper cylinder by small portions at a
time, carefully shaking the plant a little after each addition,
in order that its leaves may be covered, and that no bubbles of
air may be left. The plant and its mould are now allowed to dry,
and the yielding nature of the paper allows the loamy coating to
shrink from the outside. When this is dry it is surrounded by a
coarser substance; and, finally, we have the twig with all its
leaves embedded in a perfect mould. This mould is carefully
dried, and then gradually heated to a red heat. At the ends of
some of the leaves or shoots, wires have been left to afford
airholes by their removal, and in this state of strong ignition a
stream of air is directed into the hole formed by the end of the
branch. The consequence is, that the wood and leaves which had
been turned into charcoal by the fire, are now converted into
carbonic acid by the current of air; and, after some time, the
whole of the solid matter of which the plant consisted is
completely removed, leaving a hollow mould, bearing on its
interior all the minutest traces of its late vegetable occupant.
When this process is completed, the mould being still kept at
nearly a red heat, receives the fluid metal, which, by its
weight, either drives the very small quantity of air, which at
that high temperature remains behind, out very through the
airholes, or compresses it into the pores of very porous
substance of which the mould is formed.
108. When the form of the object intended to be cast is such
that the pattern cannot be extricated from its mould of sand or
plaster, it becomes necessary to make the pattern with wax, or
some other easily fusible substance. The sand or plaster is
moulded round this pattern, and, by the application of heat, the
wax is extricated through an opening left purposely for its
escape.
109. It is often desirable to ascertain the form of the
internal cavities, inhabited by molluscous animals, such as those
of spiral shells, and of the various corals. This may be
accomplished by filling them with fusible metal, and dissolving
the substance of the shell by muriatic acid; thus a metallic
solid will remain which exactly filled all the cavities. If such
forms are required in silver, or any other difficulty fusible
metal, the shells may be filled with wax or resin, then dissolved
away; and the remaining waxen form may serve as the pattern from
which a plaster mould may be made for casting the metal. Some
nicety will be required in these operations; and perhaps the
minuter cavities can only be filled under an exhausted receiver.
110. Casting in plaster. This is a mode of copying applied to
a variety of purposes: to produce accurate representations of the
human form--of statues--or of rare fossils--to which latter
purpose it has lately been applied with great advantage. In all
casting, the first process is to make the mould; and plaster is
the substance which is almost always employed for the purpose.
The property which it possesses of remaining for a short time in
a state of fluidity, renders it admirably adapted to this object,
and adhesion, even to an original of plaster, is effectually
prevented by oiling the surface on which it is poured. The mould
formed round the subject which is copied, removed in separate
pieces and then reunited, is that in which the copy is cast. This
process gives additional utility and value to the finest works of
art. The students of the Academy at Venice are thus enabled to
admire the sculptured figures of Egina, preserved in the gallery
at Munich; as well as the marbles of the Parthenon, the pride of
our own Museum. Casts in plaster of the Elgin marbles adorn many
of the academies of the Continent; and the liberal employment of
such presents affords us an inexpensive and permanent source of
popularity.
111. Casting in wax. This mode of copying, aided by proper
colouring, offers the most successful imitations of many objects
of natural history, and gives an air of reality to them which
might deceive even the most instructed. Numerous figures of
remarkable persons, having the face and hands formed in wax, have
been exhibited at various times; and the resemblances have, in
some instances been most striking. But whoever would see the art
of copying in wax carried to the highest perfection, should
examine the beautiful collection of fruit at the house of the
Horticultural Society; the model of the magnificent flower of the
new genus Rafflesia--the waxen models of the internal parts of
the human body which adorn the anatomical gallery of the Jardin
des Plantes at Paris, and the Museum at Florence--or the
collection of morbid anatomy at the University of Bologna. The
art of imitation by wax does not usually afford the multitude of
copies which flow from many similar operations. This number is
checked by the subsequent stages of the process, which, ceasing
to have the character of copying by a tool or pattern, become
consequently more expensive. In each individual production, form
alone is given by casting; the colouring must be the work of the
pencil, guided by the skill of the artist.
Of copying by moulding
112. This method of producing multitudes of individuals
having an exact resemblance to each other in external shape, is
adopted very widely in the arts. The substances employed are,
either naturally or by artificial preparation, in a soft or
plastic state; they are then compressed by mechanical force,
sometimes assisted by heat, into a mould of the required form.
113. Of bricks and tiles. An oblong box of wood fitting upon
a bottom fixed to the brickmaker's bench, is the mould from which
every brick is formed. A portion of the plastic mixture of which
the bricks consist is made ready by less skilful hands: the
workman first sprinkles a little sand into the mould, and then
throws the clay into it with some force; at the same time rapidly
working it with his fingers, so as to make it completely close up
to the corners. He next scrapes off, with a wetted stick, the
superfluous clay, and shakes the new-formed brick dexterously out
of its mould upon a piece of board, on which it is removed by
another workman to the place appointed for drying it. A very
skilful moulder has occasionally, in a long summer's day,
delivered from ten to eleven thousand bricks; but a fair average
day's work is from five to six thousand. Tiles of various kinds
and forms are made of finer materials, but by the same system of
moulding. Among the ruins of the city of Gour, the ancient
capital of Bengal, bricks are found having projecting ornaments
in high relief: these appear to have been formed in a mould, and
subsequently glazed with a coloured glaze. In Germany, also,
brickwork has been executed with various ornaments. The cornice
of the church of St Stephano, at Berlin, is made of large blocks
of brick moulded into the form required by the architect. At the
establishment of Messrs Cubitt, in Gray's Inn Lane, vases,
cornices, and highly ornamented capitals of columns are thus
formed which rival stone itself in elasticity, hardness, and
durability.
114. Of embossed china. Many of the forms given to those
beautiful specimens of earthenware which constitute the equipage
of our breakfast and our dinner-tables, cannot be executed in the
lathe of the potter. The embossed ornaments on the edges of the
plates, their polygonal shape, the fluted surface of many of the
vases, would all be difficult and costly of execution by the
hand; but they become easy and comparatively cheap, when made by
pressing the soft material out of which they are formed into a
hard mould. The care and skill bestowed on the preparation of
that mould are repaid by the multitude it produces. In many of
the works of the china manufactory, one part only of the article
is moulded; the upper surface of the plate, for example, whilst
the under side is figured by the lathe. In some instances, the
handle, or only a few ornaments, are moulded, and the body of the
work is turned.
115. Glass seals. The process of engraving upon gems requires
considerable time and skill. The seals thus produced can
therefore never become common. Imitations, however, have been
made of various degrees of resemblance. The colour which is given
to glass is, perhaps, the most successful part of the imitation.
A small cylindrical rod of coloured glass is heated in the flame
of a blowpipe, until the extremity becomes soft. The operator
then pinches it between the ends of a pair of nippers, which are
formed of brass, and on one side of which the device intended for
the seal has been carved in relief. When the mould has been well
finished and care is taken in heating the glass properly, the
seals thus produced are not bad imitations; and by this system of
copying they are so multiplied, that the more ordinary kinds are
sold at Birmingham for three pence a dozen.
116. Square glass bottles. The round forms which are usually
given to vessels of glass are readily produced by the expansion
of the air with which they are blown. It is, however, necessary
in many cases to make bottles of a square form, and each capable
of holding exactly the same quantity of fluid. It is also
frequently desirable to have imprinted on them the name of the
maker of the medicine or other liquid they are destined to
contain. A mould of iron, or of copper, is provided of the
intended size, on the inside of which are engraved the names
required. This mould, which is used in a hot state, opens into
two parts, to allow the insertion of the round, unfinished
bottle, which is placed in it in a very soft state before it is
removed from the end of the iron tube with which it was blown.
The mould is now closed, and the glass is forced against its
sides, by blowing strongly into the bottle.
117. Wooden snuff boxes. Snuff boxes ornamented with devices,
in imitation of carved work or of rose engine turning, are sold
at a price which proves that they are only imitations. The wood,
or horn, out of which they are formed, is softened by long
boiling in water, and whilst in this state it is forced into
moulds of iron, or steel, on which are cut the requisite
patterns, where it remains exposed to great pressure until it is
dry.
118. Horn knife handles and umbrella handles. The property
which horn possesses of becoming soft by the action of water and
of heat, fits it for many useful purposes. It is pressed into
moulds, and becomes embossed with figures in relief, adapted to
the objects to which it is to be applied. If curved, it may be
straightened; or if straight, it may be bent into any forms which
ornament or utility may require; and by the use of the mould
these forms may be multiplied in endless variety. The commoner
sorts of knives, the crooked handles for umbrellas, and a
multitude of other articles to which horn is applied, attest the
cheapness which the art of copying gives to the things formed of
this material.
119. Moulding tortoise-shell. The same principle is applied
to things formed out of the shell of the turtle, or the land
tortoise. From the greatly superior price of the raw material,
this principle of copying is, however, more rarely employed upon
it; and the few carvings which are demanded, are usually
performed by hand.
120. Tobacco-pipe making. This simple art is almost entirely
one of copying. The moulds are formed of iron, in two parts, each
embracing one half of the stem; the line of junction of these
parts may generally be observed running lengthwise from one end
of the pipe to the other. The hole passing to the bowl is formed
by thrusting a long wire through the clay before it is enclosed
in the mould. Some of the moulds have figures, or names, sunk in
the inside, which give a corresponding figure in relief upon the
finished pipe.
121. Embossing upon calico. Calicoes of one colour, but
embossed all over with raised patterns, though not much worn in
this country, are in great demand in several foreign markets.
This appearance is produced by passing them between rollers, on
one of which is figured in intaglio the pattern to be transferred
to the calico. The substance of the cloth is pressed very
forcibly into the cavities thus formed, and retains its pattern
after considerable use. The watered appearance in the cover of
the volume in the reader's hands is produced in a similar manner.
A cylinder of gun-metal, on which the design of the watering is
previously cut, is pressed by screws against another cylinder,
formed out of pieces of brown paper which have been strongly
compressed together and accurately turned. The two cylinders are
made to revolve rapidly, the paper one being slightly damped,
and, after a few minutes, it takes an impression from the upper
or metal one. The glazed calico is now passed between the
rollers, its glossy surface being in contact with the metal
cylinder, which is kept hot by a heated iron enclosed within it.
Calicoes are sometimes watered by placing two pieces on each
other in such a position that the longitudinal threads of the one
are at right angles to those of the other, and compressing them
in this state between flat rollers. The threads of the one piece
produce indentations in those of the other, but they are not so
deep as when produced by the former method.
122. Embossing upon leather. This art of copying from
patterns previously engraved on steel rollers is in most respects
similar to the preceding. The leather is forced into the
cavities, and the parts which are not opposite to any cavity are
powerfully condensed between the rollers.
123. Swaging. This is an art of copying practised by the
smith. In order to fashion his iron and steel into the various
forms demanded by his customers, he has small blocks of steel
into which are sunk cavities of different shapes; these are
called swages, and are generally in pairs. Thus if he wants a
round bolt, terminating in a cylindrical head of larger diameter,
and having one or more projecting rims, he uses a corresponding
swaging tool; and having heated the end of his iron rod, and
thickened it by striking the end in the direction of the axis
(which is technically called upsetting), he places its head upon
one part of the lage; and whilst an assistant holds the other
part on the top of the hot iron, he strikes it several times with
his hammer, occasionally turning the head one quarter round. The
heated iron is thus forced by the blows to assume the form of the
mould into which it is impressed.
124. Engraving by pressure. This is one of the most beautiful
examples of the art of copying carried to an almost unlimited
extent; and the delicacy with which it can be executed, and the
precision with which the finest traces of the graving tool can be
transferred from steel to copper, or even from hard steel to soft
steel, is most unexpected. We are indebted to Mr Perkins for most
of the contrivances which have brought this art at once almost to
perfection. An engraving is first made upon soft steel, which is
hardened by a peculiar process without in the least injuring its
delicacy. A cylinder of soft steel, pressed with great force
against the hardened steel engraving, is now made to roll very
slowly backward and forward over it, thus receiving the design,
but in relief. The cylinder is in its turn hardened without
injury., and if it be slowly rolled to and fro with strong
pressure on successive plates of copper, it will imprint on a
thousand of them a perfect facsimile of the original steel
engraving from which it was made. Thus the number of copies
producible from the same design may be multiplied a
thousand-fold. But even this is very far short of the limits to
which the process may be extended. The hardened steel roller,
bearing the design upon it in relief may be employed to make a
few of its first impressions upon plates of soft steel, and these
being hardened become the representatives of the original
engraving, and may in their turn be made the parents of other
rollers, each generating copperplates like their prototype. The
possible extent to which facsimiles of one original engraving may
thus be multiplied, almost confounds the imagination, and appears
to be for all practical purposes unlimited.
This beautiful art was first proposed by Mr Perkins for the
purpose of rendering the forgery of bank notes a matter of great
difficulty; and there are two principles which peculiarly adapt
it to that object: first, the perfect identity of all the
impressions, so that any variation in the minutest line would at
once cause detection; secondly, that the original plates may be
formed by the united labours of several artists most eminent in
their respective departments; for as only one original of each
design is necessary, the expense, even of the most elaborate
engraving, will be trifling, compared with the multitude of
copies produced from it.
125. It must, however, be admitted that the principle of
copying itself furnishes an expedient for imitating any engraving
or printed pattern, however complicated; and thus presents a
difficulty which none of the schemes devised for the prevention
of forgery appear to have yet effectually obviated. In attempting
to imitate the most perfect banknote, the first process would be
to place it with the printed side downwards upon a stone or other
substance, on which, by passing it through a rolling-press, it
might be firmly fixed. The next object would be to discover some
solvent which should dissolve the paper, but neither affect the
printing-ink, nor injure the stone or substance to which it is
attached. Water does not seem to do this effectually, and perhaps
weak alkaline or acid solutions would be tried. If, however, this
could be fully accomplished, and if the stone or other substance,
used to retain the impression, had those properties which enable
us to print from it, innumerable facsimiles of the note might
obviously be made, and the imitation would be complete. Porcelain
biscuit, which has recently been used with a black lead pencil
for memorandum books, seems in some measure adapted for such
trials, since its porosity may be diminished to any required
extent by regulating the dilution of the glazing.
126. Gold and silver moulding. Many of the mouldings used by
jewellers consist of thin slips of metal, which have received
their form by passing between steel rollers, on which the pattern
is embossed or engraved; thus taking a succession of copies of
the devices intended.
127. Ornamental papers. Sheets of paper coloured or covered
with gold or silver leaf, and embossed with various patterns, are
used for covering books, and for many ornamental purposes. The
figures upon these are produced by the same process, that of
passing the sheets of paper between engraved rollers.
Of copying by stamping
128. This mode of copying is extensively employed in the
arts. It is generally executed by means of large presses worked
with a screw and heavy flywheel. The materials on which the
copies are impressed are most frequently metals, and the process
is sometimes executed when they are hot, and in one case when the
metal is in a state between solidity and fluidity.
129. Coins and medals. The whole of the coins which circulate
as money are produced by this mode of copying. The screw presses
are either worked by manual labour, by water, or by steam power.
The mint which was sent a few years since to Calcutta was capable
of coining 200,000 pieces a day. Medals, which usually have their
figures in higher relief than coins, are produced by similar
means; but a single blow is rarely sufficient to bring them to
perfection, and the compression of the metal which arises from
the first blow renders it too hard to receive many subsequent
blows without injury to the die. It is therefore, after being
struck, removed to a furnace, in which it is carefully heated
red-hot and annealed, after which operation it is again placed
between the dies, and receives additional blows. For medals, on
which the figures are very prominent, these processes must be
repeated many times. One of the largest medals hitherto struck
underwent them nearly a hundred times before it was completed.
130. Ornaments for military accoutrements, and furniture.
These are usually of brass, and are stamped up out of solid or
sheet brass by placing it between dies, and allowing a heavy
weight to drop upon the upper die from a height of from five to
fifteen feet.
131. Buttons and nail heads. Buttons embossed with crests or
other devices are produced by the same means; and some of those
which are plain receive their hemispherical form from the dies in
which they are struck. The heads of several kinds of nails which
are portions of spheres, or polyhedrons, are also formed by these
means.
132. Of a process for copying, called in France clichee. This
curious method of copying by stamping is applied to medals, and
in some cases to forming stereotype plates. There exists a range
of temperature previous to the melting point of several of the
alloys of lead, tin, and antimony, in which the compound is
neither solid, nor yet fluid. In this kind of pasty state it is
placed in a box under a die, which descends upon it with
considerable force. The blow drives the metal into the finest
lines of the die, and the coldness of the latter immediately
solidifies the whole mass. A quantity of the half-melted metal is
scattered in all directions by the blow, and is retained by the
sides of the box in which the process is carried on. The work
thus produced is admirable for its sharpness, but has not the
finished form of a piece just leaving the coining-press: the
sides are ragged, and it must be trimmed, and its thickness
equalized in the lathe.
Of copying by punching
133. This mode of copying consists in driving a steel punch
through the substance to be cut, either by a blow or by pressure.
In some cases the object is to copy the aperture, and the
substance separated from the plate is rejected; in other cases
the small pieces cut out are the objects of the workman's labour.
134. Punching iron plate for boilers. The steel punch used
for this purpose is from three-eighths to three-quarters of an
inch in diameter, and drives out a circular disk from a plate of
iron from one-quarter to five eighths of an inch thick.
135. Punching tinned iron. The ornamental patterns of open
work which decorate the tinned and japanned wares in general use,
are rarely punched by the workman who makes them. In London the
art of punching out these patterns in screw-presses is carried on
as a separate trade; and large quantities of sheet tin are thus
perforated for cullenders, wine-strainers, borders of waiters,
and other similar purposes. The perfection and the precision to
which the art has been carried are remarkable. Sheets of copper,
too, are punched with small holes about the hundredth of an inch
in diameter, in such multitudes that more of the sheet metal is
removed than remains behind; and plates of tin have been
perforated with above three thousand holes in each square inch.
136. The inlaid plates of brass and rosewood, called buhl
work, which ornament our furniture, are, in some instances,
formed by punching; but in this case, both the parts cut out, and
those which remain, are in many cases employed. In the remaining
illustrations of the art of copying by punching, the part made
use of is that which is punched out.
137. Cards for guns. The substitution of a circular disk of
thin card instead of paper, for retaining in its place the charge
of a fowling-piece, is attended with considerable advantage. It
would, however, be of little avail, unless an easy method was
contrived of producing an unlimited number of cards, each exactly
fitting the bore of the barrel. The small steel tool used for
this purpose cuts out innumerable circles similar to its cutting
end, each of which precisely fills the barrel for which it was
designed.
138. Ornaments of gilt paper. The golden stars, leaves, and
other devices, sold in shops for the purpose of ornamenting
articles made of paper and pasteboard, and other fancy works, are
cut by punches of various forms out of sheets of gilt paper.
139. Steel chains. The chain used in connecting the
mainspring and fusee in watches and clocks, is composed of small
pieces of sheet steel, and it is of great importance that each of
these pieces should be of exactly the same size. The links are of
two sorts; one of them consisting of a single oblong piece of
steel with two holes in it, and the other formed by connecting
two of the same pieces of steel, placed parallel to each other,
and at a small distance apart, by two rivets. The two kinds of
links occur alternately in the chain: each end of the single
pieces being placed between the ends of two others, and connected
with them by a rivet passing through all three. If the rivet
holes in the pieces for the double links are not precisely at
equal distances, the chain will not be straight, and will,
consequently, be unfit for its purpose.
Copying with elongation
140. In this species of copying there exists but little
resemblance between the copy and the original. It is the
cross-section only of the thing produced which is similar to the
tool through which it passes. When the substances to be operated
upon are hard, they must frequently pass in succession through
several holes, and it is in some cases necessary to anneal them
at intervals.
141. Wire drawing. The metal to be converted into wire is
made of a cylindrical form, and drawn forcibly through circular
holes in plates of steel: at each passage it becomes smaller.
and, when finished, its section at any point is a precise copy of
the last hole through which it passed. Upon the larger kinds of
wire, fine lines may sometimes be traced, running longitudinally.
these arise from slight imperfections in the holes of the
draw-plates. For many purposes of the arts, wire, the section of
which is square or half round, is required: the same method of
making it is pursued, except that the holes through which it is
drawn are in such cases themselves square, or half-round, or of
whatever other form the wire is required to be. A species of wire
is made, the section of which resembles a star with from six to
twelve rays; this is called pinion wire, and is used by the
clockmakers. They file away all the rays from a short piece,
except from about half an inch near one end: this becomes a
pinion for a clock; and the leaves or teeth are already burnished
and finished, from having passed through the draw-plate.
142. Tube drawing. The art of forming tubes of uniform
diameter is nearly similar in its mode of execution to wire
drawing. The sheet brass is bent round and soldered so as to form
a hollow cylinder; and if the diameter outside is that which is
required to be uniform, it is drawn through a succession of
holes, as in wire drawing: If the inside diameter is to be
uniform, a succession of steel cylinders, called triblets, are
drawn through the brass tube. In making tubes for telescopes, it
is necessary that both the inside and outside should be uniform.
A steel triblet, therefore, is first passed into the tube, which
is then drawn through a succession of holes, until the outside
diameter is reduced to the required size. The metal of which the
tube is formed is condensed between these holes and the steel
cylinder within; and when the latter is withdrawn the internal
surface appears polished. The brass tube is considerably extended
by this process, sometimes even to double its first length.
143. Leaden pipes. Leaden pipes for the conveyance of water
were formerly made by casting; but it has been found that they
can be made both cheaper and better by drawing them through holes
in the manner last described. A cylinder of lead, of five or six
inches in diameter and about two feet long, is cast with a small
hole through its axis, and an iron triblet of about fifteen feet
in length is forced into the hole. It is then drawn through a
series of holes, until the lead is extended upon the triblet from
one end to the other, and is of the proper thickness in
proportion to the size of the pipe.
144. Iron rolling. When cylinders of iron of greater
thickness than wire are required, they are formed by passing
wrought iron between rollers, each of which has sunk in it a
semi-cylindrical groove; and as such rollers rarely touch
accurately, a longitudinal line will usually be observed in the
cylinders so manufactured. Bar iron is thus shaped into all the
various forms of round, square, half-round, oval, etc. in which
it occurs in commerce. A particular species of moulding is thus
made, which resembles, in its section, that part of the frame of
a window which separates two adjacent panes of glass. Being much
stronger than wood, it can be considerably reduced in thickness,
and consequently offers less obstruction to the light; it is much
used for skylights.
145. It is sometimes required that the iron thus produced
should not be of uniform thickness throughout. This is the case
in bars for railroads, where greater depth is required towards
the middle of the rail which is at the greatest distance from the
supports. This form is produced by cutting the groove in the
rollers deeper at those parts where additional strength is
required, so that the hollow which surrounds the roller would, if
it could be unwound, be a mould of the shape the iron is intended
to fit.
146. Vermicelli. The various forms into which this paste is
made are given by forcing it through holes in tin plate. It
passes through them, and appears on the other side in long
strings. The cook makes use of the same method in preparing
butter and ornamental pastry for the table, and the confectioner
in forming cylindrical lozenges of various composition.
Of copying with altered dimensions
147. Of the pentagraph. This mode of copying is chiefly used
for drawings or maps: the instrument is simple; and, although
usually employed in reducing, is capable of enlarging the size of
the copy. An automaton figure, exhibited in London a short time
since, which drew profiles of its visitors, was regulated by a
mechanism on this principle. A small aperture in the wall,
opposite the seat in which the person is placed whose profile is
taken, conceals a camera lucida, which is placed in an adjoining
apartment: and an assistant, by moving a point, connected by a
pentagraph with the hand of the automaton, over the outline of
the head, causes the figure to trace a corresponding profile.
148. By turning. The art of turning might perhaps itself be
classed amongst the arts of copying. A steel axis, called a
mandril, having a pulley attached to the middle of it, is
supported at one end either by a conical point, or by a
cylindrical collar, and at the other end by another collar,
through which it passes. The extremity which projects beyond this
last collar is formed into a screw, by which various instruments,
called chucks, can be attached to it. These chucks are intended
to hold the various materials to be submitted to the operation of
turning, and have a great variety of forms. The mandril with the
chuck is made to revolve by a strap which passes over the pulley
that is attached to it, and likewise over a larger wheel moved
either by the foot, or by its connection with steam or water
power. All work which is executed on a mandril partakes in some
measure of the irregularities in the form of that mandril; and
the perfect circularity of section which ought to exist in every
part of the work, can only be ensured by an equal accuracy in the
mandril and its collar.
149. Rose engine turning. This elegant art depends in a great
measure on copying. Circular plates of metal called rosettes,
having various indentations on the surfaces and edges, are fixed
on the mandril, which admits of a movement either end-wise or
laterally: a fixed obstacle called the 'touch', against which the
rosettes are pressed by a spring, obliges the mandril to follow
their indentations, and thus causes the cutting tool to trace out
the same pattern on the work. The distance of the cutting tool
from the centre being usually less than the radius of the
rosette, causes the copy to be much diminished.
150. Copying dies. A lathe has been long known in France, and
recently been used at the English mint for copying dies. A blunt
point is carried by a very slow spiral movement successively over
every part of the die to be copied, and is pressed by a weight
into all the cavities; while a cutting point connected with it by
the machine traverses the face of a piece of soft steel, in which
it cuts the device of the original die on the same or on a
diminished scale. The degree of excellence of the copy increases
in proportion as it is smaller than the original. The die of a
crown-piece will furnish by copy a very tolerable die for a
sixpence. But the chief use to be expected from this lathe is to
prepare all the coarser parts, and leave only the finer and more
expressive lines for the skill and genius of the artist.
151. Shoe-last making engine. An instrument not very unlike
in principle was proposed for the purpose of making shoe lasts. A
pattern last of a shoe for the right foot was placed in one part
of the apparatus, and when the machine was moved, two pieces of
wood, placed in another part which had been previously adjusted
by screws, were cut into lasts greater or less than the original,
as was desired; and although the pattern was for the right foot,
one of the lasts was for the left, an effect which was produced
by merely interposing a wheel which reversed the motion between
the two pieces of wood to be cut into lasts.
152. Engine for copying busts. Many years since, the late Mr
Watt amused himself with constructing an engine to produce copies
of busts or statues, either of the same size as the original, or
in a diminished proportion. The substances on which he operated
were various, and some of the results were shewn to his friends,
but the mechanism by which they were made has never been
described. More recently, Mr Hawkins, who, nearly at the same
time, had also contrived a similar machine, has placed it in the
hands of an artist, who has made copies in ivory from a variety
of busts. The art of multiplying in different sizes the figures
of the sculptor, aided by that of rendering their acquisition
cheap through the art of casting, promises to give additional
value to his productions, and to diffuse more widely the pleasure
arising from their possession.
153. Screw cutting. When this operation is performed in the
lathe by means of a screw upon the mandril, it is essentially an
art of copying, but it is only the number of threads in a given
length which is copied; the form of the thread, and length as
well as the diameter of the screw to be cut, are entirely
independent of those from which the copy is made. There is
another method of cutting screws in a lathe by means of one
pattern screw, which, being connected by wheels with the mandril,
guides the cutting point. In this process, unless the time of
revolution of the mandril is the same as that of the screw which
guides the cutting point, the number of threads in a given length
will be different. If the mandril move quicker than the cutting
point, the screw which is produced will be finer than the
original; if it move slower, the copy will be more coarse than
the original. The screw thus generated may be finer or coarser--
it may be larger or smaller in diameter--it may have the same or
a greater number of threads than that from which it is copied;
yet all the defects which exist in the original will be
accurately transmitted, under the modified circumstances, to
every individual generated from it.
154. Printing from copper plates with altered dimensions.
Some very singular specimens of an art of copying, not yet made
public, were brought from Paris a few years since. A watchmaker
in that city, of the name of Gonord, had contrived a method by
which he could take from the same copperplate impressions of
different sizes, either larger or smaller than the original
design. Having procured four impressions of a parrot, surrounded
by a circle, executed in this manner, I shewed them to the late
Mr Lowry, an engraver equally distinguished for his skill, and
for the many mechanical contrivances with which he enriched his
art. The relative dimensions of the several impressions were 5.5,
6.3, 8.4, 15.0, so that the largest was nearly three times the
linear size of the smallest; and Mr Lowry assured me, that he was
unable to detect any lines in one which had not corresponding
lines in the others. There appeared to be a difference in the
quantity of ink, but none in the traces of the engraving; and,
from the general appearance, it was conjectured that the largest
but one was the original impression from the copperplate.
The means by which this singular operation was executed have
not been published; but two conjectures were formed at the time
which merit notice. It was supposed that the artist was in
possession of some method of transferring the ink from the lines
of a copperplate to the surface of some fluid, and of
retransferring the impression from the fluid to paper. If this
could be accomplished, the print would, in the first instance, be
of exactly the same size as the copper from which it was derived;
but if the fluid were contained in a vessel having the form of an
inverted cone, with a small aperture at the bottom, the liquid
might be lowered or raised in the vessel by gradual abstraction
or addition through the apex of the cone; in this case, the
surface to which the printing-ink adhered would diminish or
enlarge, and in this altered state the impression might be
retransferred to paper. It must be admitted, that this
conjectural explanation is liable to very considerable
difficulties; for, although the converse operation of taking an
impression from a liquid surface has a parallel in the art of
marbling paper, the possibility of transferring the ink from the
copper to the fluid requires to be proved.
Another and more plausible explanation is founded on the
elastic nature of the compound of glue and treacle, a substance
already in use in transferring engravings to earthenware. It is
conjectured, that an impression from the copperplate is taken
upon a large sheet of this composition; that this sheet is then
stretched in both directions, and that the ink thus expanded is
transferred to paper. If the copy is required to be smaller than
the original, the elastic substance must first be stretched, and
then receive the impression from the copperplate: on removing the
tension it will contract, and thus reduce the size of the design.
It is possible that one transfer may not in all cases suffice; as
the extensibility of the composition of glue and treacle,
although considerable, is still limited. Perhaps sheets of India
rubber of uniform texture and thickness, may be found to answer
better than this composition; or possibly the ink might be
transferred from the copper plate to the surface of a bottle of
this gum, which bottle might, after being expanded by forcing air
into it, give up the enlarged impression to paper. As it would
require considerable time to produce impressions in this manner,
and there might arise some difficulty in making them all of
precisely the same size, the process might be rendered more
certain and expeditious by performing that part of the operation
which depends on the enlargement or diminution of the design only
once; and, instead of printing from the soft substance.
transferring the design from it to stone: thus a considerable
portion of the work would be reduced to an art already well
known, that of lithography. This idea receives some confirmation
from the fact, that in another set of specimens, consisting of a
map of St Petersburgh, of several sizes, a very short line,
evidently an accidental defect, occurs in all the impressions of
one particular size, but not in any of a different size.
155. Machine to produce engraving from medals. An instrument
was contrived, a long time ago, and is described in the Manuel de
Tourneur, by which copperplate engravings are produced from
medals and other objects in relief. The medal and the copper are
fixed on two sliding plates at right angles to each other, so
connected that, when the plate on which the medal is fixed is
raised vertically by a screw, the slide holding the copperplate
is advanced by an equal quantity in the horizontal direction. The
medal is fixed on the vertical slide with its face towards the
copperplate, and a little above it.
A bar, terminating at one end in a tracing point, and at the
other in a short arm, at right angles to the bar, and holding a
diamond point, is placed horizontally above the copper; so that
the tracing point shall touch the medal to which the bar is
perpendicular, and the diamond point shall touch the copperplate
to which the arm is perpendicular.
Under this arrangement, the bar being supposed to move
parallel to itself, and consequently to the copper, if the
tracing point pass over a flat part of the medal, the diamond
point will draw a straight line of equal length upon the copper;
but, if the tracing point pass over any projecting part of the
medal, the deviation from the straight line by the diamond point,
will be exactly equal to the elevation of the corresponding point
of the medal above the rest of the surface. Thus, by the transit
of this tracing point over any line upon the medal, the diamond
will draw upon the copper a section of the medal through that
line.
A screw is attached to the apparatus, so that if the medal be
raised a very small quantity by the screw, the copperplate will
be advanced by the same quantity, and thus a new line of section
may be drawn: and, by continuing this process, the series of
sectional lines on the copper produces the representation of the
medal on a plane: the outline and the form of the figure arising
from the sinuosities of the lines, and from their greater or less
proximity. The effect of this kind of engraving is very striking;
and in some specimens gives a high degree of apparent relief. It
has been practised on plate glass, and is then additionally
curious from the circumstance of the fine lines traced by the
diamond being invisible, except in certain lights.
From this description, it will have been seen that the
engraving on copper must be distorted; that is to say, that the
projection on the copper cannot be the same as that which arises
from a perpendicular projection of each point of the medal upon a
plane parallel to itself. The position of the prominent parts
will be more altered than that of the less elevated; and the
greater the relief of the medal the more distorted will be its
engraved representation. Mr John Bate, son of Mr Bate, of the
Poultry, has contrived an improved machine, for which he has
taken a patent, in which this source of distortion is remedied.
The head, in the title page of the present volume, is copied from
a medal of Roger Bacon, which forms one of a series of medals of
eminent men, struck at the Royal Mint at Munich, and is the first
of the published productions of this new art.(3*)
The inconvenience which arises from too high a relief in the
medal, or in the bust, might be remedied by some mechanical
contrivance, by which the deviation of the diamond point from the
right line (which it would describe when the tracing point
traverses a plane), would be made proportional not to the
elevation of the corresponding point above the plane of the
medal, but to its elevation above some other parallel plane
removed to a fit distance behind it. Thus busts and statues might
be reduced to any required degree of relief.
156. The machine just described naturally suggests other
views which seem to deserve some consideration, and, perhaps,
some experiment. If a medal were placed under the tracing point
of a pentagraph, an engraving tool substituted for the pencil,
and a copperplate in the place of the paper; and if, by some
mechanism, the tracing point, which slides in a vertical plane,
could, as it is carried over the different elevations of the
medal, increase or diminish the depth of the engraved line
proportionally to the actual height of the corresponding point on
the medal, then an engraving would be produced, free at least
from any distortion, although it might be liable to objections of
a different kind. If, by any similar contrivance, instead of
lines, we could make on each point of the copper a dot, varying
in size or depth with the altitude of the corresponding point of
the medal above its plane, than a new species of engraving would
be produced: and the variety of these might again be increased,
by causing the graving point to describe very small circles, of
diameters, varying with the height of the point on the medal
above a given plane; or by making the graving tool consist of
three equidistant points, whose distance increased or diminished
according to some determinate law, dependent on the elevation of
the point represented above the plane of the medal. It would,
perhaps, be difficult to imagine the effects of some of these
kinds of engraving; but they would all possess, in common, the
property of being projections, by parallel lines, of the objects
represented, and the intensity of the shade of the ink would
either vary according to some function of the distance of the
point represented from some given plane, or it would be a little
modified by the distances from the same plane of a few of the
immediately contiguous points.
157. The system of shading maps by means of lines of equal
altitude above the sea bears some analogy to this mode of
representing medals, and if applied to them would produce a
different species of engraved resemblance. The projections on the
plane of the medal, of the section of an imaginary plane, placed
at successive distances above it, with the medal itself, would
produce a likeness of the figure on the medal, in which all the
inclined parts of it would be dark in proportion to their
inclination. Other species of engraving might be conceived by
substituting, instead of the imaginary plane, an imaginary sphere
or other solid, intersecting the figure in the medal.
158. Lace made by caterpillars. A most extraordinary species
of manufacture, which is in a slight degree connected with
copying, has been contrived by an officer of engineers residing
at Munich. It consists of lace, and veils, with open patterns in
them, made entirely by caterpillars. The following is the mode of
proceeding adopted: he makes a paste of the leaves of the plant,
which is the usual food of the species of caterpillar(4*) he
employs, and spreads it thinly over a stone, or other flat
substance. He then, with a camel-hair pencil dipped in olive oil,
draws upon the coating of paste the pattern he wishes the insects
to leave open. This stone is then placed in an inclined position,
and a number of the caterpillars are placed at the bottom. A
peculiar species is chosen, which spins a strong web; and the
animals commencing at the bottom, eat and spin their way up to
the top, carefully avoiding every part touched by the oil, but
devouring all the rest of the paste. The extreme lightness of
these veils, combined with some strength, is truly surprising.
One of them, measuring twenty-six and a half inches by seventeen
inches, weighed only 1.51 grains; a degree of lightness which
will appear more strongly by contrast with other fabrics. One
square yard of the substance of which these veils are made weighs
4 1/3 grains, whilst one square yard of silk gauze weighs 137
grains, and one square yard of the finest patent net weighs 262
1/2 grains. The ladies' coloured muslin dresses, mentioned in the
table subjoined, cost ten shillings per dress, and each weigh six
ounces; the cotton from which they are made weighing nearly six
and two-ninth ounces avoirdupois weight.
Weight of one square yard of each of the following articles(5*)
Weight of
Weight cotton used
Value finished of in waking
per yard one square one square
Description of goods measure yard yard
s. d. Troy grains Troy grains
Caterpillar veils -- 4 1/3 --
Silk gauze 3-4 wide 1 0 137 --
Finest patent net -- 262 1/2 --
Fine cambric muslin -- 551 --
6-4ths jaconet muslin 2 0 613 670
Ladies' coloured muslin dresses 3 0 788 875
6-4ths cambric 1 2 972 1069
9-8ths calico 0 9 988 1085
1/2-yard nankeen 0 8 2240 2432
159. This enumeration, which is far from complete, of the
arts in which copying is the foundation, may be terminated with
an example which has long been under the eye of the reader;
although few, perhaps, are aware of the number of repeated
copyings of which these very pages are the subject.
1. They are copies, by printing, from stereotype plates.
2. These stereotype plates are copied, by the art of casting,
from moulds formed of plaster of Paris.
3. These moulds are themselves copied by casting the plaster
in a liquid state upon the moveable types set up by the
compositor.
[It is here that the union of the intellectual and the
mechanical departments takes place. The mysteries, however, of an
author's copying, form no part of our enquiry, although it may be
fairly remarked, that, in numerous instances, the mental far
eclipses the mechanical copyist.]
4. These moveable types, the obedient messengers of the most
opposite thoughts, the most conflicting theories, are themselves
copies by casting from moulds of copper called matrices.
5. The lower part of those matrices, bearing the impressions
of the letters or characters, are copies, by punching, from steel
punches on which the same characters exist in relief.
6. These steel punches are not themselves entirely exempted
from the great principle of art. Many of the cavities which exist
in them, such as those in the middle of the punches for the
letters a, b, d, e, g, etc., are produced from other steel
punches in which these parts are in relief.
We have thus traced through six successive stages of copying
the mechanical art of printing from stereotype plates: the
principle of copying contributing in this, as in every other
department of manufacture, to the uniformity and the cheapness of
the work produced.
NOTES:
1. The late Mr Lowry.
2. I posses a lithographic reprint of a page of a table, which
appears, from the from of the type, to have been several years
old.
3. The construction of the engraving becomes evident on examining
it with a lens of sufficient power to show the continuity of the
lines.
4. The Phalaena pardilla, which feeds on the Prunus padus.
5. Some of these weights and measures are calculated from a
statement in the Report of the Committee of the House of Commons
on Printed Cotton Goods; and the widths of the pieces there given
are presumed to be the real widths, not those by which they are
called in the retail shops.
Chapter 12
On the Method of Observing Manufacturies
160. Having now reviewed the mechanical principles which
regulate the successful application of mechanical science to
great establishments for the production of manufactured goods, it
remains for us to suggest a few enquiries, and to offer a few
observations, to those whom an enlightened curiosity may lead to
examine the factories of this or of other countries.
The remark--that it is important to commit to writing all
information as soon as possible after it is received, especially
when numbers are concerned--applies to almost all enquiries. It
is frequently impossible to do this at the time of visiting an
establishment, although not the slightest jealousy may exist; the
mere act of writing information as it is communicated orally, is
a great interruption to the examination of machinery. In such
cases, therefore, it is advisable to have prepared beforehand the
questions to be asked, and to leave blanks for the answers, which
may be quickly inserted, as, in a multitude of cases, they are
merely numbers. Those who have not tried this plan will be
surprised at the quantity of information which may, through its
means, be acquired, even by a short examination. Each manufacture
requires its own list of questions, which will be better drawn up
after the first visit. The following outline, which is very
generally applicable, may suffice for an illustration; and to
save time, it may be convenient to have it printed; and to bind
up, in the form of a pocket-book, a hundred copies of the
skeleton forms for processes, with about twenty of the general
enquiries.
GENERAL ENQUIRIES
Outlines of a description of any of the mechanical arts ought to
contain information on the following points
Brief sketch of its history, particularly the date of its
invention, and of its introduction into England.
Short reference to the previous states through which the
material employed has passed: the places whence it is procured:
the price of a given quantity.
[The various processes must now be described successively
according to the plan which will be given in (161); after which
the following information should be given.]
Are various kinds of the same article made in one establishment,
or at different ones, and are there differences in the processes?
To what defects are the goods liable?
What substitutes or adulterations are used?
What waste is allowed by the master?
What tests are there of the goodness of the manufactured
articles?
The weight of a given quantity, or number, and a comparison
with that of the raw material?
The wholesale price at the manufactory? (L s. d.) per ( )
The usual retail price? (L s. d.)
Who provide tools? Master, or men? Who repair tools? Master,
or men?
What is the expense of the machinery?
What is the annual wear and tear, and what its duration?
Is there any particular trade for making it? Where?
Is it made and repaired at the manufactory?
In any manufactory visited, state the number ( ) of
processes; and of the persons employed in each process; and the
quantity of manufactured produce.
What quantity is made annually in Great Britain?
Is the capital invested in manufactories large or small?
Mention the principal seats of this manufacture in England;
and if it flourishes abroad, the places where it is established.
The duty, excise. or bounty, if any, should be stated, and
any alterations in past years; and also the amount exported or
imported for a series of years.
Whether the same article, but of superior, equal, or inferior
make, is imported?
Does the manufacturer export, or sell, to a middleman, who
supplies the merchant?
To what countries is it chiefly sent? and in what goods are
the returns made?
161. Each process requires a separate skeleton, and the
following outline will be sufficient for many different
manufactories:
Process ( ) Manufacture ( )
Place ( ) Name ( )
date 183
The mode of executing it, with sketches of the tools or
machine if necessary.
The number of persons necessary to attend the machine. Are
the operatives men. ( ) women, ( ) or children? ( ) If mixed,
what are the proportions?
What is the pay of each? (s. d.) (s. d. ) (s. d.) per ( )
What number ( ) of hours do they work per day?
Is it usual, or necessary, to work night and day without
stopping? Is the labour performed by piece--or by day-work?
Who provide tools? Master, or men? Who repair tools? Master,
or men? What degree of skill is required, and how many years' ( )
apprenticeship?
The number of times ( ) the operation is repeated per day or
per hour?
The number of failures ( ) in a thousand?
Whether the workmen or the master loses by the broken or
damaged articles?
What is done with them?
If the same process is repeated several times, state the
diminution or increase of measure, and the loss, if any, at each
repetition.
162. In this skeleton, the answers to the questions are in
some cases printed, as "Who repair the tools?--Masters, Men"; in
order that the proper answer may be underlined with a pencil. In
filling up the answers which require numbers, some care should be
taken: for instance, if the observer stands with his watch in his
hand before a person heading a pin, the workman will almost
certainly increase his speed, and the estimate will be too large.
A much better average will result from enquiring what quantity is
considered a fair day's work. When this cannot be ascertained,
the number of operations performed in a given time may frequently
be counted when the workman is quite unconscious that any person
is observing him. Thus the sound made by the motion of a loom may
enable the observer to count the number of strokes per minute,
even though he is outside the building in which it is contained.
M. Coulomb, who had great experience in making such observations,
cautions those who may repeat his experiments against being
deceived by such circumstances: 'Je prie' (says he) 'ceux qui
voudront les repeter, s'ils n'ont pas le temps de mesurer les
resultats apres plusiers jours d'un travail continu, d'observer
les ouvriers a differentes reprises dans la journee, sans qu'ils
sachent qu'ils sont observes. L'on ne peut trop avertir combien
l'on risque de se tromper en calculant, soit la vitesse, soit le
temps effectif du travail, d'apres une observation de quelques
minutes.' Memoires de l'Institut. vol. II, p. 247. It frequently
happens, that in a series of answers to such questions, there are
some which, although given directly, may also be deduced by a
short calculation from others that are given or known; and
advantage should always be taken of these verifications, in order
to confirm the accuracy of the statements; or, in case they are
discordant, to correct the apparent anomalies. In putting lists
of questions into the hands of a person undertaking to give
information upon any subject, it is in some cases desirable to
have an estimate of the soundness of his judgement. The questions
can frequently be so shaped, that some of them may indirectly
depend on others; and one or two may be inserted whose answers
can be obtained by other methods: nor is this process without its
advantages in enabling us to determine the value of our own
judgement. The habit of forming an estimate of the magnitude of
any object or the frequency of any occurrence, immediately
previous to our applying to it measure or number, tends
materially to fix the attention and to improve the judgement.
Section II
On the domestic and political economy of manufactures
Chapter 13
Distinction Between Making and Manufacturing
163. The economical principles which regulate the application
of machinery, and which govern the interior of all our great
factories, are quite as essential to the prosperity of a great
commercial country, as are those mechanical principles, the
operation of which has been illustrated in the preceding section.
The first object of every person who attempts to make any
article of consumption, is, or ought to be, to produce it in a
perfect form; but in order to secure to himself the greatest and
most permanent profit, he must endeavour, by every means in his
power, to render the new luxury or want which he has created,
cheap to those who consume it. The larger number of purchasers
thus obtained will, in some measure, secure him from the caprices
of fashion, whilst it furnishes a far greater amount of profit,
although the contribution of each individual is diminished. The
importance of collecting data, for the purpose of enabling the
manufacturer to ascertain how many additional customers he will
acquire by a given reduction in the price of the article he
makes, cannot be too strongly pressed upon the attention of those
who employ themselves in statistical enquiries. In some ranks of
society, no diminution of price can bring forward a great
additional number of customers; whilst, amongst other classes, a
very small reduction will so enlarge the sale, as to yield a
considerable increase of profit. Materials calculated to assist
in forming a table of the numbers of persons who possess incomes
of different amount, occur in the 14th Report of the
Commissioners of Revenue Inquiry, which includes a statement of
the amount of personal property proved at the legacy office
during one year; the number of the various classes of testators;
and an account of the number of persons receiving dividends from
funded property, distributed into classes. Such a table, formed
even approximately, and exhibited in the form of a curve, might
be of service.
164. A considerable difference exists between the terms
making and manufacturing. The former refers to the production of
a small, the latter to that of a very large number of
individuals; and the difference is well illustrated in the
evidence, given before the Committee of the House of Commons, on
the Export of Tools and Machinery. On that occasion Mr Maudslay
stated, that he had been applied to by the Navy Board to make
iron tanks for ships, and that he was rather unwilling to do so,
as he considered it to be out of his line of business; however,
he undertook to make one as a trial. The holes for the rivets
were punched by hand-punching with presses, and the 1680 holes
which each tank required cost seven shillings. The Navy Board,
who required a large number, proposed that he should supply forty
tanks a week for many months. The magnitude of the order made it
worth his while to commence manufacture, and to make tools for
the express business. Mr Maudslay therefore offered, if the Board
would give him an order for two thousand tanks, to supply them at
the rate of eighty per week. The order was given: he made tools,
by which the expense of punching the rivet-holes of each tank was
reduced from seven shillings to ninepence; he supplied
ninety-eight tanks a week for six months, and the price charged
for each was reduced from seventeen pounds to fifteen.
165. If, therefore, the maker of an article wish to become a
manufacturer, in the more extended sense of the term, he must
attend to other principles besides those mechanical ones on which
the successful execution of his work depends; and he must
carefully arrange the whole system of his factory in such a
manner, that the article he sells to the public may be produced
at as small a cost as possible. Should he not be actuated at
first by motives so remote, he will, in every highly civilized
country, be compelled, by the powerful stimulus of competition,
to attend to the principles of the domestic economy of
manufactures. At every reduction in price of the commodity he
makes, he will be driven to seek compensation in a saving of
expense in some of the processes; and his ingenuity will be
sharpened in this enquiry by the hope of being able in his turn
to undersell his rivals. The benefit of the improvements thus
engendered is, for a short time, confined to those from whose
ingenuity they derive their origin; but when a sufficient
experience has proved their value, they become generally adopted,
until in their turn they are superseded by other more economical
methods.
Chapter 14
Of Money as a Medium of Exchange
166. In the earlier stages of societies the interchange of
the few commodities required was conducted by barter, but as soon
as their wants became more varied and extensive, the necessity of
having some common measure of the value of all commodities--
itself capable of subdivision--became apparent: thus money was
introduced. In some countries shells have been employed for this
purpose; but civilized nations have, by common consent, adopted
the precious metals.(1*) The sovereign power has, in most
countries, assumed the right of coining; or, in other words, the
right of stamping with distinguishing marks, pieces of metal
having certain forms and weights and a certain degree of
fineness: the marks becoming a guarantee, to the people amongst
whom the money circulates, that each piece is of the required
weight and quality.
The expense of manufacturing gold into coin, and that of the
loss arising from wear, as well as of interest on the capital
invested in it, must either be defrayed by the State, or be
compensated by a small reduction in its weight, and is a far less
cost to the nation than the loss of time and inconvenience which
would arise from a system of exchange or barter.
167. These coins are liable to two inconveniences: they may
be manufactured privately by individuals, of the same quality,
and similarly stamped; or imitations may be made of inferior
metal, or of diminished weight. The first of these inconveniences
would be easily remedied by making the current value of the coin
nearly equal to that of the same weight of the metal; and the
second would be obviated by the caution of individuals in
examining the external characters of each coin, and partly by the
punishment inflicted by the State on the perpetrators of such
frauds.
168. The subdivisions of money vary in different countries,
and much time may be lost by an inconvenient system of division.
The effect is felt in keeping extensive accounts, and
particularly in calculating the interest on loans, or the
discount upon bills of exchange. The decimal system is the best
adapted to facilitate all such calculations; and it becomes an
interesting question to consider whether our own currency might
not be converted into one decimally divided. The great step, that
of abolishing the guinea, has already been taken without any
inconvenience, and but little is now required to render the
change complete.
169. If, whenever it becomes necessary to call in the
half-crowns, a new coin of the value of two shillings were
issued, which should be called by some name implying a unit (a
prince, for instance), we should have the tenth part of a
sovereign. A few years after, when the public were familiar with
this coin, it might be divided into one hundred instead of
ninety-six farthings; and it would then consist of twenty-five
pence, each of which would be four per cent. less in value than
the former penny. The shillings and six-pences being then
withdrawn from circulation, their place might be supplied with
silver coins each worth five of the new pence, and by others of
ten-pence, and of twopence halfpenny; the latter coin, having a
distinct name, would be the tenth part of a prince.
170. The various manufactured commodities, and the various
property possessed by the inhabitants of a country, all become
measured by the standard thus introduced. But it must be observed
that the value of gold is itself variable; and that, like all
other commodities, its price depends on the extent of the demand
compared with that of the supply.
171. As transactions multiply, and the sums to be paid become
large, the actual transfer of the precious metals from one
individual to another is attended with inconvenience and
difficulty, and it is found more convenient to substitute written
promises to pay on demand specified quantities of gold. These
promises are called bank-notes; and when the person or body
issuing them is known to be able to fulfil the pledge, the note
will circulate for a long time before it gets into the hands of
any person who may wish to make use of the gold it represents.
These paper representatives supply the place of a certain
quantity of gold; and, being much cheaper, a large portion of the
expense of a metallic circulation is saved by their employment.
172. As commercial transactions increase, the transfer of
bank-notes is, to a considerable extent, superseded by shorter
processes. Banks are established, into which all monies are paid,
and out of which all payments are made, through written orders
called checks, drawn by those who keep accounts with them. In a
large capital, each bank receives, through its numerous
customers, checks payable by every other; and if clerks were sent
round to receive the amount in banknotes due from each, it would
occupy much time, and be attended with some risk and
inconvenience.
173. Clearing house. In London this is avoided, by making all
checks paid in to bankers pass through what is technically called
The Clearing House. In a large room in Lombard Street, about
thirty clerks from the several London bankers take their
stations, in alphabetical order, at desks placed round the room;
each having a small open box by his side, and the name of the
firm to which he belongs in large characters on the wall above
his head. From time to time other clerks from every house enter
the room, and, passing along, drop into the box the checks due by
that firm to the house from which this distributor is sent. The
clerk at the table enters the amount of the several checks in a
book previously prepared, under the name of the bank to which
they are respectively due.
Four o'clock in the afternoon is the latest hour to which the
boxes are open to receive checks; and at a few minutes before
that time, some signs of increased activity begin to appear in
this previously quiet and business-like scene. Numerous clerks
then arrive, anxious to distribute, up to the latest possible
moment, the checks which have been paid into the houses of their
employers.
At four o'clock all the boxes are removed, and each clerk
adds up the amount of the checks put into his box and payable by
his own to other houses. He also receives another book from his
own house, containing the amounts of the checks which their
distributing clerk has put into the box of every other banker.
Having compared these, he writes out the balances due to or from
his own house, opposite the name of each of the other banks; and
having verified this statement by a comparison with the similar
list made by the clerks of those houses, he sends to his own bank
the general balance resulting from this sheet, the amount of
which, if it is due from that to other houses, is sent back in
bank-notes.
At five o'clock the Inspector takes his seat; when each
clerk, who has upon the result of all the transactions a balance
to pay to various other houses, pays it to the inspector, who
gives a ticket for the amount. The clerks of those houses to whom
money is due, then receive the several sums from the inspector,
who takes from them a ticket for the amount. Thus the whole of
these payments are made by a double system of balance, a very
small amount of bank-notes passing from hand to hand, and
scarcely any coin.
174. It is difficult to form a satisfactory estimate of the
sums which daily pass through this operation: they fluctuate from
two millions to perhaps fifteen. About two millions and a half
may possibly be considered as something like an average,
requiring for its adjustment, perhaps, L200,000 in bank notes and
L20 in specie. By an agreement between the different bankers, all
checks which have the name of any firm written across them must
pass through the clearing house: consequently, if any such check
should be lost, the firm on which it is drawn would refuse to pay
it at the counter; a circumstance which adds greatly to the
convenience of commerce.
The advantage of this system is such, that two meetings a day
have been recently established--one at twelve, the other at
three o'clock; but the payment of balances takes place once only,
at five o'clock.
If all the private banks kept accounts with the Bank of
England, it would be possible to carry on the whole of these
transactions with a still smaller quantity of circulating medium.
175. In reflecting on the facility with which these vast
transactions are accomplished--supposing, for the sake of
argument, that they form only the fourth part of the daily
transactions of the whole community--it is impossible not to be
struck with the importance of interfering as little as possible
with their natural adjustment. Each payment indicates a transfer
of property made for the benefit of both parties; and if it were
possible, which it is not, to place, by legal or other means,
some impediment in the way which only amounted to one-eighth per
cent, such a species of friction would produce a useless
expenditure of nearly four millions annually: a circumstance
which is deserving the attention of those who doubt the good
policy of the expense incurred by using the precious metals for
one portion of the currency of the country.
176. One of the most obvious differences between a metallic
and a paper circulation is, that the coin can never, by any panic
or national danger, be reduced below the value of bullion in
other civilized countries; whilst a paper currency may, from the
action of such causes, totally lose its value. Both metallic and
paper money, it is true, may be depreciated, but with very
different effects.
1. Depreciation of coin. The state may issue coin of the same
nominal value, but containing only half the original quantity of
gold, mixed with some cheap alloy; but every piece so issued
bears about with it internal evidence of the amount of the
depreciation: it is not necessary that every successive
proprietor should analyse the new coin; but a few having done so,
its intrinsic worth becomes publicly known. Of course the coin
previously in circulation is now more valuable as bullion, and
quickly disappears. All future purchases adjust themselves to the
new standard, and prices are quickly doubled; but all past
contracts also are vitiated, and all persons to whom money is
owing, if compelled to receive payment in the new coin, are
robbed of one-half of their debt, which is confiscated for the
benefit of the debtor.
2. Depreciation of paper. The depreciation of paper money
follows a different course. If, by any act of the Government
paper is ordained to be a legal tender for debts, and, at the
same time, ceases to be exchangeable for coin, those who have
occasion to purchase of foreigners, who are not compelled to take
the notes, will make some of their payments in gold; and if the
issue of paper, unchecked by the power of demanding the gold it
represents, be continued, the whole of the coin will soon
disappear. But the public, who are obliged to take the notes, are
unable, by any internal evidence, to detect the extent of their
depreciation; it varies with the amount in circulation, and may
go on till the notes shall be worth little more than the paper on
which they are printed. During the whole of this time every
creditor is suffering to an extent which he cannot measure; and
every bargain is rendered uncertain in its advantage, by the
continually changing value of the medium through which it is
conducted. This calamitous course has actually been run in
several countries: in France, it reached nearly its extreme limit
during the existence of assignats. We have ourselves experienced
some portion of the misery it creates; but by a return to sounder
principles, have happily escaped the destruction and ruin which
always attends the completion of that career.
177. Every person in a civilized country requires, according
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