On the Division of Labour
241. We have already mentioned
what may, perhaps, appear paradoxical to some of our
readers that the division of labour can be applied
with equal success to mental as to mechanical operations,
and that it ensures in both the same economy of time.
A short account of its practical application, in the
most extensive series of calculations ever executed,
will offer an interesting illustration of this fact,
whilst at the same time it will afford an occasion
for shewing that the arrangements which ought to regulate
the interior economy of a manufactory, are founded
on principles of deeper root than may have been supposed,
and are capable of being usefully employed in preparing
the road to some of the sublimest investigations of
the human mind.
242. In the midst of that excitement
which accompanied the Revolution of France and the
succeeding wars, the ambition of the nation, unexhausted
by its fatal passion for military renown, was at the
same time directed to some of the nobler and more
permanent triumphs which mark the era of a people’s
greatness and which receive the applause of posterity
long after their conquests have been wrested from
them, or even when their existence as a nation may
be told only by the page of history. Amongst
their enterprises of science, the French Government
was desirous of producing a series of mathematical
tables, to facilitate the application of the decimal
system which they had so recently adopted. They
directed, therefore, their mathematicians to construct
such tables, on the most extensive scale. Their
most distinguished philosophers, responding fully to
the call of their country, invented new methods for
this laborious task; and a work, completely answering
the large demands of the Government, was produced
in a remarkably short period of time. M. Prony,
to whom the superintendence of this great undertaking
was confided, in speaking of its commencement, observes:
Je m’y livrai avec toute l’ardeur dont
j’etois capable, et je m’occupai d’abord
du plan general de l’execution. Toutes
les conditions que j’avois a remplir
necessitoient l’emploi d’un grand nombre
de calculateurs; et il me vint bientot a la pensee
d’appliquer a la connection de ces Tables la
division du travail, dont les Arts de Commerce tirent
un parti si avantageux pour reunir a la pernection
de main-d’oeuvre l’economie de la depense
et du temps. The circumstance which gave rise
to this singular application of the principle of the
division on labour is so interesting, that no apology
is necessary for introducing it from a small pamphlet
printed at Paris a few years since, when a proposition
was made by the English to the French Government,
that the two countries should print these tables at
their joint expense.
243. The origin of the idea is
related in the following extract:
C’est a un chapitre d’un
ouvrage Anglais,(1) justement celebre, (I.) qu’est
probablement due l’existence de l’ouvrage
dont le gouvernement Britannique veut faire jouir
le monde savant:
Voici l’anecdote: M. de
Prony s’etait engage. avec les comites de gouvernement.
a composer pour la division centesimale du cercle,
des tables logarithmiques et trigonometriques, qui,
non seulement ne laissassent rien a desirer quant a
l’exactitude, mais qui formassent le monument
de calcul 1e plus vaste et le plus imposant qui eut
jamais ete execute, ou meme concu. Les logarithmes
des nombres de 1 a 200.000 formaient a ce travail un
supplement necessaire et exige. Il fut aise a
M. de Prony de s’assurer que meme en s’associant
trois ou quatre habiles co-operateurs. La plus
grande duree presumable de sa vie ne lui sufirai pas
pour remplir ses engagements. Il etait occupe
de cette facheuse pensee lorsque. Se trouvant
devant la boutique d’un marchand de livres.
Il appercut la belle edition Anglaise de Smith, donnee
a Londres en 1776: il ouvrit le livre au hazard.
et tomba sur le premier chapitre, qui traite de la
division du travail, et ou la fabrication des epingles
est citee pour exemple. A peine avait-il
parcouru les premieres pages, que, par une espece
d’inspiration. il concut l’expedient de
mettre ses logarithmes en manufacture comme les epingles.
Il faisait en ce moment, a l’ecole polytechnique,
des lecons sur une partie d’analyse liee a ce
genre de travail, la methode des differences, et ses
applications a l’interpolation. Il alla
passer quelques jours a la campagne. et revint a Paris
avec le plan de fabrication. qui a ete suivi dans
l’execution. Il rassembla deux ateliers.
qui faisai ent separement les memes calculs, et se
servaient de verification reciproque.(2)
244. The ancient methods of computing
tables were altogether inapplicable to such a proceeding.
M. Prony, therefore, wishing to avail himself of all
the talent of his country in devising new methods,
formed the first section of those who were to take
part in this enterprise out of five or six of the
most eminent mathematicians in France.
First section. The duty of this
first section was to investigate, amongst the various
analytical expressions which could be found for the
same function, that which was most readily adapted
to simple numerical calculation by many individuals
employed at the same time. This section had little
or nothing to do with the actual numerical work.
When its labours were concluded, the formulae on the
use of which it had decided, were delivered to the
second section.
Second section. This section
consisted of seven or eight persons of considerable
acquaintance with mathematics: and their duty
was to convert into numbers the formulae put into their
hands by the first section an operation of great labour;
and then to deliver out these formulae to the members
of the third section, and receive from them the finished
calculations. The members of this second section
had certain means of verifying the calculations without
the necessity of repeating, or even of examining,
the whole of the work done by the third section.
Third section. The members of
this section, whose number varied from sixty to eighty,
received certain numbers from the second section,
and, using nothing more than simple addition and subtraction,
they returned to that section the tables in a finished
state. It is remarkable that nine-tenths of this
class had no knowledge of arithmetic beyond the two
first rules which they were thus called upon to exercise,
and that these persons were usually found more correct
in their calculations, than those who possessed a
more extensive knowledge of the subject.
245. When it is stated that the
tables thus computed occupy seventeen large folio
volumes, some idea may perhaps be formed of the labour.
From that part executed by the third class, which may
almost be termed mechanical, requiring the least knowledge
and by far the greatest exertions, the first class
were entirely exempt. Such labour can always
be purchased at an easy rate. The duties of the
second class, although requiring considerable skill
in arithmetical operations, were yet in some measure
relieved by the higher interest naturally felt in
those more difficult operations. The exertions
of the first class are not likely to require, upon
another occasion, so much skill and labour as they
did upon the first attempt to introduce such a method;
but when the completion of a calculating engine shall
have produced a substitute for the whole of the third
section of computers, the attention of analysts will
naturally be directed to simplifying its application,
by a new discussion of the methods of converting analytical
formulae into numbers.
246. The proceeding of M. Prony,
in this celebrated system of calculation, much resembles
that of a skilful person about to construct a cotton
or silk mill, or any similar establishment. Having,
by his own genius, or through the aid of his friends,
found that some improved machinery may be successfully
applied to his pursuit, he makes drawings of his plans
of the machinery, and may himself be considered as
constituting the first section. He next requires
the assistance of operative engineers capable of executing
the machinery he has designed, some of whom should
understand the nature of the processes to be carried
on; and these constitute his second section.
When a sufficient number of machines have been made,
a multitude of other persons, possessed of a lower
degree of skill, must be employed in using them; these
form the third section: but their work, and the
just performance of the machines, must be still superintended
by the second class.
247. As the possibility of performing
arithmetical calculations by machinery may appear
to non-mathematical readers to be rather too large
a postulate, and as it is connected with the subject
of the division of labour, I shall here endeavour,
in a few lines, to give some slight perception of
the manner in which this can be done—and
thus to remove a small portion of the veil which covers
that apparent mystery.
248. That nearly all tables of
numbers which follow any law, however complicated,
may be formed, to a greater or less extent, solely
by the proper arrangement of the successive addition
and subtraction of numbers befitting each table, is
a general principle which can be demonstrated to those
only who are well acquainted with mathematics; but
the mind, even of the reader who is but very slightly
acquainted with that science, will readily conceive
that it is not impossible, by attending to the following
example.
The subjoined table is the beginning
of one in very extensive use, which has been printed
and reprinted very frequently in many countries, and
is called a table of square numbers.
Terms of Table A Table B first Difference C second Difference
1 1
3
2 4 2
5
3 9 2
7
4 16 2
9
5 25 2
11
6 36 2
13
7 49
Any number in the table, column A,
may be obtained, by multiplying the number which expresses
the distance of that term from the commencement of
the table by itself; thus, 25 is the fifth term from
the beginning of the table, and 5 multiplied by itself,
or by 5, is equal to 25. Let us now subtract each
term of this table from the next succeeding term,
and place the results in another column (B), which
may be called first difference column. If we
again subtract each term of this first difference
from the succeeding term, we find the result is always
the number 2, (column C); and that the same number
will always recur in that column, which may be called
the second difference, will appear to any person who
takes the trouble to carry on the table a few terms
further. Now when once this is admitted, it is
quite clear that, provided the first term (1) of the
table, the first term (3) of the first differences,
and the first term (2) of the second or constant difference,
are originally given, we can continue the table of
square numbers to any extent, merely by addition:
for the series of first differences may be formed by
repeatedly adding the constant difference (2) to (3)
the first number in column B, and we then have the
series of numbers, 3, 5, 6, etc.: and again,
by successively adding each of these to the first
number (1) of the table, we produce the square numbers.
249. Having thus, I hope, thrown
some light upon the theoretical part of the question,
I shall endeavour to shew that the mechanical execution
of such an engine, as would produce this series of
numbers, is not so far removed from that of ordinary
machinery as might be conceived.(3*) Let the reader
imagine three clocks, placed on a table side by side,
each having only one hand, and each having a thousand
divisions instead of twelve hours marked on the face;
and every time a string is pulled, let them strike
on a bell the numbers of the divisions to which their
hands point. Let him further suppose that two
of the clocks, for the sake of distinction called
B and C, have some mechanism by which the clock C
advances the hand of the clock B one division, for
each stroke it makes upon its own bell: and let
the clock B by a similar contrivance advance the hand
of the clock A one division, for each stroke it makes
on its own bell. With such an arrangement, having
set the hand of the clock A to the division I, that
of B to iii, and that of C to ii, let the
reader imagine the repeating parts of the clocks to
be set in motion continually in the following order:
viz.—pull the string of clock A; pull
the string of clock B; pull the string of clock C.
The table on the following page will
then express the series of movements and their results.
If now only those divisions struck
or pointed at by the clock A be attended to and written
down, it will be found that they produce the series
of the squares of the natural numbers. Such a
series could, of course, be carried by this mechanism
only so far as the numbers which can be expressed
by three figures; but this may be sufficient to give
some idea of the construction—and was,
in fact, the point to which the first model of the
calculating engine, now in progress, extended.
250. We have seen, then, that
the effect of the division of labour, both in mechanical
and in mental operations, is, that it enables us to
purchase and apply to each process precisely that
quantity of skill and knowledge which is required for
it: we avoid employing any part of the time of
a man who can get eight or ten shillings a day by
his skill in tempering needles, in turning a wheel,
which can be done for sixpence a day; and we equally
avoid the loss arising from the employment of an accomplished
mathematician in performing the lowest processes of
arithmetic.
251. The division of labour cannot
be successfully practised unless there exists a great
demand for its produce; and it requires a large capital
to be employed in those arts in which it is used.
In watchmaking it has been carried, perhaps, to the
greatest extent. It was stated in evidence before
a committee of the House of Commons, that there are
a hundred and two distinct branches of this art, to
each of which a boy may be put apprentice: and
that he only learns his master’s department,
and is unable, after his apprenticeship has expired,
without subsequent instruction, to work at any other
branch. The watch-finisher, whose business is
to put together the scattered parts, is the only one,
out of the hundred and two persons, who can work in
any other department than his own.
252. In one of the most difficult
arts, that of mining, great improvements have resulted
from the judicious distribution of the duties; and
under the arrangments which have gradually been introduced,
the whole system of the mine and its government is
now placed under the control of the following officers.
1. A manager, who has the general
knowledge of all that is to be done, and who may be
assisted by one or more skilful persons.
2. Underground captains direct
the proper mining operations, and govern the working
miners.
3. The purser and book-keeper manage the accounts.
4. The engineer erects the engines,
and superintends the men who work them.
5. A chief pitman has charge
of the pumps and the apparatus of the shafts.
6. A surface-captain, with assistants,
receives the ores raised, and directs the dressing
department, the object of which is to render them
marketable.
7. The head carpenter superintends
many constructions.
8. The foreman of the smiths
regulates the ironwork and tools.
9. A materials man selects, purchases,
receives and delivers all articles required.
10. The roper has charge of ropes
and cordage of all sorts.
Notes:
1. An Enquiry into the Nature
and Causes of the Wealth of Nations, by Adam Smith.
2. Note sur la publication, proposee
par le gouvernement Anglais des grandes tables logarithmiques
et trigonometriques de M de Prony De l’imprimerie
de F. Didot, December 1, 1829, p. 7
3. Since the publication of the
second edition of this work, one portion of the engine
which I have been constructing for some years past
has been put together. It calculates, in three
columns, a table with its first and second differences.
Each column can be expressed as far as five figures,
so that these fifteen figures constitute about one
ninth part of the larger engine. The ease and
precision with which it works leave no room to doubt
its success in the more extended form. Besides
tables of squares, cubes, and portions of logarithmic
tables, it possesses the power of calculating certain
series whose differences are not constant; and it
has already tabulated parts of series formed from
the following equations:
The third differential of ux = units
figur of delta ux
The third differential of ux = nearest
whole no. to (1/10,000 delta ux)
The subjoined is one amongst the series
which it has calculated:
0 3,486 42,972
0 4,991 50,532
1 6,907 58,813
14 9,295 67,826
70 12,236 77,602
230 15,741 88,202
495 19,861 99,627
916 24,597 111,928
1,504 30,010 125,116
2,340 36,131 139,272
The general term of this is,
ux = (x(x-1)(x-2))/(1 X 2 X 3)
+ the whole number in x/10 + 10 Sigma^3 (units figure
of (x(x-1)/2)