IELTS Reading: Table completion

There is no lead in a pencil and there never has been. The writing material is graphite, a form of carbon whose atoms lie in sheets that slide over one another readily, which is why it leaves a mark on paper and why it feels slippery between the fingers. The confusion is old and comes from a mistake of identification: when an extraordinary deposit was found in Cumberland in the 1560s, the black substance was taken for a variety of lead ore and named accordingly, and the name stayed long after the chemistry was understood.

That deposit, at Borrowdale, is the reason the pencil exists in the form it does. It was the only large body of solid graphite pure enough to be sawn into sticks and used directly ever found anywhere; every other source in the world required the material to be ground and reconstituted. The sticks marked paper beautifully and marked the hand equally well, so they were first wrapped in string that could be unwound as the point wore down, and later enclosed in a wooden case. The English had a monopoly on the material for two centuries, and the mine was worked only a few weeks a year, guarded by armed men and deliberately flooded between workings to prevent theft.

The monopoly ended not with a discovery but with a war. Cut off from English graphite during the conflicts of the 1790s, the French government asked an officer named Nicolas-Jacques Conté to find a substitute, and within a few days he had one. Powdered graphite of ordinary quality, mixed with clay, moulded into rods and fired in a kiln, produced a usable core from material that had been useless before. It also produced something the Borrowdale sticks never could: a range. The more clay in the mixture, the harder the core and the paler the line it leaves; the more graphite, the softer and the blacker. Every grading system in use since, with its H for hard and B for black, descends directly from a wartime expedient.

Modern manufacture would be recognisable to a worker of the 1860s. A slat of wood about the length of a pencil and the width of several is machined with parallel grooves; the cores are laid into the grooves; a second grooved slat is glued on top, making a sandwich; and when the glue has set the sandwich is cut lengthwise and shaped, so that a single pair of slats yields eight or nine finished pencils at once. The painting, the ferrule and the eraser are afterthoughts added in the nineteenth century, and the hexagonal cross section exists because a round pencil rolls off a sloping desk.

The wood is a more demanding requirement than it appears. It has to be soft enough to be cut by a small blade held in the hand, without splintering, and it must cut as cleanly across the grain as along it, since a sharpener does both. Very few timbers manage this. The industry used red cedar from the eastern United States until the supply was exhausted, at which point it moved to incense cedar from California, which remains the standard; substitutes have been tried repeatedly and most of them tear.

Given how much has been invented since, it is worth asking why the pencil is still made in billions. It writes upside down, at any angle, in extreme cold, on damp paper and in a vacuum, none of which a ballpoint pen reliably manages. It requires no power, no cartridge and no maintenance beyond a blade. Its mark can be removed and, if it is not removed, will still be legible in three hundred years, because graphite is chemically inert in a way that no ink is. For a certain range of tasks nothing has ever improved on it, and the range includes several that matter.

There is a well-known essay which observes that no single person on earth knows how to make one. The claim sounds like a rhetorical flourish and survives inspection. Making a pencil requires cedar, which requires forestry, saws and the steel to make saws; graphite from one continent and clay from another; a kiln, and the fuel and refractory materials a kiln needs; glue, lacquer, brass for the ferrule and rubber for the eraser, each with its own supply chain reaching back through mining, chemistry and transport. The person operating the machine that cuts the slats knows nothing about vulcanising rubber, and does not need to.

That is the pencil's real interest. It is among the cheapest manufactured objects in existence, costing less than a few minutes of anybody's labour, and it is the product of a coordination that nobody designed and nobody oversees. The person who wants one does not have to know any of this, and would not be able to obtain one if they did, because knowing how a pencil is made is not the same as being able to make one, and no amount of study closes the gap.