More Notes on the Division Of Labour (Part One)

A correspondent questions Adam Smith’s arithmetic in his well-known example of the ‘pin factory’, in particular about the “astonishing” production feat of conducting thousands of operations needed to produce “12 pounds of pins a day” (Wealth Of Nations).

Smith’s life-long habit of visiting places of manufacturing and commerce are attested to by Ian Ross, in his definitive biography, The Life of Adam Smith, 2nd edition, 2011, Oxford University Press (and mentioned by his first biographer, Dugald Stewart, 1793).   There were several nail factories or nail producing parts of general workshops in the Kirkcaldy area, where Smith grew up before he went to Glasgow University in 1737.  His mother’s family was well connected in the town and in their farms nearby, and in Kirkcaldy’s busy little estuary fishing port, where his father had been the Customs Officer.  He said he visited a small nail factory that employed 10 men, but does not say where.  He certainly visited other places of work, including a tanning factory in Glasgow and the Carron Iron Works, near Falkirk, that made ordnance for the navy, run by his friend Dr John Roebuck.  Smith took Edmund Burke to see it.

Heavy machinery was water driven. Several large machines used in pin making are illustrated in the French Encylopedie, a uniquely interesting source of information about early 18-century pin-manufacture, and many other forms of manufacture.

Crude 18th-century Pins were inches long to suit everyday clothes, not as per modern tiny pins. They were cut from brass wire. The men did not do the 18 operations; they did one operation, and some did more than one related operation.  Output per hour was different in some of the operations (cutting the brass wire, or example, compared to preparing the heads) and time was therefore available to move between other tasks and share in other operations too.

The arithmetic shares are proportioned not by what each man did to complete a single set of pins, but by the notional per capita share of the total number measured by the weight of a given output (credible comment has been offered questioning Smith’s ‘strange’ use of measuring output by weight).

One man spent 12 hours, six days a week, cutting the thin wires, presumably using a guillotine.  Could he cut the wire into 4,000 pin-sized pieces per hour? Possibly yes, if he operated a treadle machine (like on old manual sewing machines) with a metal jig to cut lengths of wire from a large spool of wire, and a bucket to catch them.  “When they exerted themselves” (no Health and Safety regulations, no Employment Protection laws), higher output was possible.  Having worked in factories as a youngster (during my long eight ’gap’ years), I remain amazed at the manual dexterity demonstrated by experienced male and female employees doing repetitive work.  Boring work, yes, but it paid well, in relative terms.

Until recently, from a reader’s correspondence, I have not seen any scepticism about the figures given by Adam Smith which he quoted, apparently, from the French Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers, edited by Denis Diderot (1713-84) and Jean le Rond d'Alembert (1717 – 29) 1783, which was perhaps inspired by the earlier English Cyclopedia (1725) and the political situation in France. A young French economist, whom I have met, J. L. Peaucelle, assessed the ‘pin factory’ example, in a credible forensic account of Smith’s French sources for the numerical data: ‘Adam Smith’s use of multiple references for his pin making examples’, European Journal of The History of Economic Thought, vol. 13, no. 4, pp 480-512. Peaucelle has identified Smith’s (unacknowledged) sources for the pin-factory data.

I reproduce the relevant passage from Wealth Of Nations, Book 1, chapter 1, with relevant emphasis in bold:

‘To take an example, therefore, from a very trifling manufacture; but one in which the division of labour has been very often taken notice of, the trade of the pin-maker; a workman not educated to this business (which the division of labour has rendered a distinct trade), nor acquainted with the use of the machinery employed in it (to the invention of which the same division of labour has probably given occasion), could scarce, perhaps, with his utmost industry, make one pin in a day, and certainly could not make twenty. But in the way in which this business is now carried on, not only the whole work is a peculiar trade, but it is divided into a number of branches, of which the greater part are likewise peculiar trades. One man draws out the wire, another straights it, a third cuts it, a fourth points it, a fifth grinds it at the top for receiving the head; to make the head requires two or three distinct operations; to put it on, is a peculiar business, to whiten the pins is another; it is even a trade by itself to put them into the paper; and the important business of making a pin is, in this manner, divided into about eighteen distinct operations, which, in some manufactories, are all performed by distinct hands, though in others the same man will sometimes perform two or three of them. I have seen a small manufactory of this kind where ten men only were employed, and where some of them consequently performed two or three distinct operations. But though they were very poor, and therefore but indifferently accommodated with the necessary machinery, they could, when they exerted themselves, make among them about twelve pounds of pins in a day. There are in a pound upwards of four thousand pins of a middling size. Those ten persons, therefore, could make among them upwards of forty-eight thousand pins in a day. Each person, therefore, making a tenth part of forty-eight thousand pins, might be considered as making four thousand eight hundred pins in a day. But if they had all wrought separately and independently, and without any of them having been educated to this peculiar business, they certainly could not each of them have made twenty, perhaps not one pin in a day; that is, certainly, not the two hundred and fortieth, perhaps not the four thousand eight hundredth part of what they are at present capable of performing, in consequence of a proper division and combination of their different operations.”