Forty Centuries of Ink / Or, A chronological narrative concerning ink and its backgrounds, introducing incidental observations and deductions, parallels of time and color phenomena, bibliography, chemistry, poetical effusions, citations, anecdotes and curiosa together with some evidence respecting the evanescent character of most inks of to-day and an epitome of chemico-legal ink.

by David Nunes Carvalho

THE black-lead pencil, under many circumstances, is a very useful substitute for the pen, in that it requires no liquid ink for marking the characters on paper or other materials. The peculiar substance which fills the central channel of the stick of cedar has the property of marking when it touches paper; and, as the marks thus made are susceptible to easy removal, a pencil of this kind is available for purposes which would not be answered by the use of pen and ink.

The substance misnamed "black-lead" contains NO LEAD and is a carburet of iron, being composed of carbon and iron. It generally occurs in Mountain districts, in small kidney-shaped pieces, varying in size from that of a pea upwards, which are interspersed among various strata, and is met with in different parts of the world.

Its principal source of supply until about 1845, when it became exhausted, was the Borrowdale mine in Cumberland, England, which was discovered in 1564. About 1852 a number of mines were opened containing this substance in Siberia and from which place the best products are now obtained.

The accidental discovery of this mineral at Borrowdale was during the reign of Queen Elizabeth who made many inquiries about it. The name of this mineral was locally known as wad (graphite). So valuable was it regarded that it commanded a very high price, and this price acted as in inducement to the workmen and others to pilfer pieces from the mine. For a number of years scenes of great commotion took place, arising out of these depredations; and the result was that the proprietors adopted such stringent rules that hardly anything was known of the internal economy of the mine till about sixty years ago, when Mr. Parkes gave a description of it, from which I may condense a few particulars.

The mine is in the midst of a mountain about two thousand feet high, which rises at in angle of about 45 degrees; and, as that part of the mine which has been worked during the last century is near the middle of the mountain, the present entrance is about a thousand feet from the summit. The opening by which the workmen enter descends by a flight of steps; and in order to guard the treasure within, the proprietors have erected a strong brick building of four rooms, one of which is immediately over the entrance into the mine. This entrance is secured by a trap-door, and the room connected with it serves as a dressing-room for the men when they enter and leave the mine. The men work in gangs, which relieve each other every six hours, and when the hour of relief comes, a steward or foreman attends the dressing- room to see the men change their dresses as they come up one by one out of the mine. The clothes are examined by the steward to see that no black-lead is concealed in them; and when the men have dressed they leave the mine, making room for another gang, who change their clothes, enter the mine, and are fastened in for six hours. In one of the four rooms of which the house consists there is a table, at which men are employed in sorting and dressing the mineral. This is necessary, because it is usually divided into two qualities, the finest of which have generally pieces of iron- ore or other impurity attached to them, which must be dressed off. These men, who are strictly watched while at work, put the dressed black-lead into casks holding about one hundred-weight each, in which state it leaves the mine. The casks are conveyed down the side of the mountain in a curious manner. Each cask is fixed upon a light sledge with two wheels, and a man, who is well used to the precipitous path, walks down in front of the sledge, taking care that it does not acquire momentum enough to overpower him. When the cask has been thus guided safely to the bottom, the man carries the sledge up hill upon his shoulders, and prepares for another descent.

Up to about the middle of the eighteenth century the mine was opened only once in seven years, the quantity taken out at each time of opening being such as was deemed sufficient to serve the market for seven years; but when, at a later period, it was found that the demand was increasing and the supply decreasing, it was deemed necessary to work the mine six or seven weeks every year. During the time of working, the mine is guarded night and day; and when a quantity sufficient for one year's consumption has been taken out, the mine is secured until the following year. Several hundred cartloads of rubbish are wheeled into the mine, so as to block up the entrance completely; and this rubbish acts as a dam to prevent the springs and land waters from flowing out, so that the mine gradually becomes flooded.

When the Year's mining is concluded, the barrels of black-lead are brought to market, and the mode of effecting the sales was described by Dr. Faraday some years ago to be as follows: A market is held on the first Monday of every month at a house in London, where the buyers, who are generally only seven or eight in number, examine each piece with a sharp instrument to ascertain its hardness, those which are too soft being rejected. The person who has the first choice pays 45s. per pound, the others 30s. But, as there is no addition made to the first quantity in the market, the residual portions are examined over and over again until they are exhausted. At one time the annual sale was said to amount to the value of L40,000 per annum, but it has been greatly reduced since.

A mode of applying manufacturing processes to the preparation of black-lead is described by Dr. Ure as being adopted in Paris. The mineral, being reduced to a fine powder, is mixed with very pure powdered clay, and the two are calcined in a crucible at a white heat; the proportion of clay employed is greater as the pencil is required to be harder, the average being equal parts of both. The ingredients are ground with a muller on a porphyry slab and then made into balls, which are preserved in a moist atmosphere in the form of paste. The paste is pressed into grooves cut in a smooth board, and another board, previously greased, is pressed down upon it. When the paste has had time to dry, the mould or grooved board is put into a moderately heated oven, by which the paste, now in the form of square pencils, shrinks sufficiently to fall out of the grooves. In order to give solidity to the pencils they are set upright in a crucible and surrounded with pounded charcoal, fine sand, or sifted ashes; the crucible, being covered, is exposed to a degree of heat proportionate to the hardness required in the pencils, the harder pencils requiring the higher degree of heat. Some of the pencils are shaped in a curious manner: models of the pencils, made of iron, are stuck upright upon an iron tray, having edges raised as high as the intended length of the pencils; and a metallic alloy, made of tin, lead, antimony and bismuth is poured into the sheet-iron tray. When the alloy has cooled, it is inverted and shaken off from the model-rods, so as to form a mass of metal perforated throughout with tubular cavities corresponding in size with the intended pencil pieces; the pencil paste is introduced by pressure into these cavities, and when nearly dry the pieces shrink sufficiently to be easily removed from the cavities.

The pencils just described are alike throughout all their thickness, but in the majority of English pencils there is a wooden holder to contain a narrow filament of black lead running down the middle. So long ago as the year 1618 this mode was adopted; for Sir John Pettus, who was deputy governor of the Borrowdale mine under Charles II, in his "Fleta Minor," while, speaking of black-lead says, that "Of late it is curiously formed into cases of deal or cedar and so sold as dry pencils, something more useful than pen and ink." In a general way modern black-lead pencils, are made by sawing cedar first into long planks, and then into smaller rods; grooves are cut out by means of a cutting machine moved by a fly- wheel to such a depth as will receive a small layer of black-lead; the pieces of the mineral are cut into thin slabs and then into rods the same size as the grooves, into which they are inserted; the two halves of the case are then glued together, and the whole is turned into a cylindrical form by means of a guage.

The kind of pencil called "crayon" is a mixture of some kind of earth with a coloring substance. The earth employed is sometimes chalk, and at other times pipe-clay, gypsum, starch-flour, or ochre. The coloring substance is yellow ochre, mineral yellow, chrome, red chalk, vermilion, indigo—indeed, any of the usual dry colors, according to the tint required. Besides the earth and the color, there is a gummy liquid required to combine them together; gum arabic, gum tragacanth, and in some cases oil, wax, or suet, are used as the third ingredient. The crayons here alluded to are employed rather for drawing than for writing, but they obviously belong to the class of pencils in their mode of action.