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The Plaster Of Paris Process

( Originally Published 1927 )



Each and every one of the inventions and processes thus far described was an important step forward in the building up of the art of stereotyping, but none of these methods was practiced to any extent by others than by the men who invented them. The adoption of stereotyping throughout the entire printing world was due to the efforts and the labors of an Englishman, CHARLES MAHON, EARL OF STANHOPE (born 1753, died 1816). Stanhope did not invent any entirely new method of stereotyping, he did, however, improve and supplement the existing methods to such a degree as to make them practicable for shop work and to insure the universal use of his perfected method.

Earl Stanhope was a most interesting but eccentric character. As a politician, he carried the liberal principles of the Whig (Liberal) party of England to such lengths that for years he was distinguished as "the minority of one." His strong interest in the prosperity of the people turned his inventive genius into a useful direction, and besides the famous printing press which bears his name, he invented consider-able improvements in the locks of canals, and two excellent calculating machines. The Earl of Stanhope revised and improved stereotyping. Altho, as stated above, the processes of the art had been completed in Edinburgh by William Ged previous to the year 1736, the invention seems to have died with him, and no attempt was made to revive it for many years. Tilloch and Foulis of Glasgow, and Didot of Paris experimented upon it, without however, meeting with appreciable success. Tilloch and Foulis had abandoned their pursuit for some years, when Stanhope offered himself as their pupil and paid 800 pounds ($4,000) for the instruction. Foulis spent some months at the Stanhope home in Chevening, initiating Stanhope in the practical part of the Tilloch and Foulis process. The first products stereotyped by Stanhope were standard school books. The process was communicated in 1803 to the University of Cambridge for the very high consideration of 4,000 pounds ($20,000) and in a year or two later to the University of Oxford; but it was probably 1807 before any works appeared by the former and 1809 from the latter.

Lord Stanhope afterwards gained the assistance of Wilson, a London printer, and with few exceptions, the knowledge of the art was confined to Mr. Wilson and those in the confidence of Stanhope and Wilson. It was endeavored to keep it most inviolably secret, and for some years the endeavors to this end were successful; Stanhope filed caveats at the British Patent office covering every step as he went on; he never, however, followed up these caveats by taking out patents on the process. Stanhope and Wilson engaged in their business a Mr. Walker, who fitted up their stereotyping foundry, when, in consequence of some misunderstanding between Stanhope and Wilson, Walker, who was also original maker of the Stanhope printing presses, was encouraged by Stanhope to set up a stereotype printing office, in opposition to Mr. Wilson; being unskilled himself in the practical part of the process, Walker was secretly instructed on this point by one of Wilson's workmen, originally recommended to Wilson by Stanhope. This proceeding on the part of Walker produced a rupture between him and Wilson, who afterwards employed an eminent engineer, Peter Kier by name, to make his stereotyping apparatus.

Kier made several important improvements on it; but a quarrel having also in a short time arisen between Wilson and him, he, in revenge, taught any person who applied to him the whole of the Stanhope process for 50 ($250), provided they gave him an order for the apparatus, for which he charged 250 ($1,250), and more. The nature of the Stanhope process thus became known; and many availed themselves of this opportunity. Lord Stanhope then edited a manual explaining his stereotyping process; it is a rather lengthy document minutely covering the following steps of the method:

Giving a list of stereotype imposing furniture necessary for one page (an iron frame, and iron side-stick and foot-stick, an iron head, and two to four iron quoins, with four bevelled brasses, to give a slope to the edges of the stereotype plate).

Instructions for the burning of the gypsum. Instructions for molding, pouring of the gypsum, etc. Instructions for the dressing of mold, making it fit for being put in the oven to be dried.

Explaining the nature and the making of oven used for baking the molds.

Instructions for process of casting.

The process practiced in the stereotype shop of Stanhope and Wilson is described as the following: The face of the types set up in the form was first rubbed with fine olive or sperm oil, in order to prevent the adhesion of the plaster of Paris mold to the form. The types having ben set with high quadrates and spaces, they were plastered over the liquid gypsum (nine parts of plaster, finely ground in a semi-liquid state from admixture with seven parts of water) to the thickness of about one-half of one inch, so that a level cake was formed on the surface of the types. As soon as the plaster hardened, which it did almost immediately, the case was separated from the types, and on being turned up, showed a complete hollow or mold-like representation of the faces of the types and everything else on the page. Then the set-up types were of no further use, and were redistributed. The cake was put into an oven and baked, like a piece of pottery. Next, it was laid on a square iron pan, having a lid of the same metal, with holes at the corners. The pan was then immersed in a pot of molten metal and being allowed to fill up by means of the holes, it was at length taken out and put aside to cool. On opening the pan, the metal had run into the mold side of the cake, and formed a thin plate all over, exhibiting the perfect appearance of the faces of the types on which the gypsum was plastered. These plates were about one-sixth of one inch thick, and were printed from in the same manner as in the case of printing from types.

About the same time when Stanhope was engaged in his experiments, POTERAL, of Paris, created a stir in the printing world by announcing that, he had invented a more simple method of stereotyping than any yet in use. A Commission of the National Institute of France was appointed to examine his claims. From its report it appears that Poteral had executed nothing according to his projected plan, which was in fact merely a modification of part of Herhahn's method. Poteral proposed to form matrices for casting hollow-faced types, instead of type in relief; to compose the pages with these types, and then to cast from them a stereo-type plate, formed of compound metal. The commission's report was entirely unfavorable and the process was never put into practice.

In 1809, CHARLES BRIGHTLY, Printer of Suffolk, published a small pamphlet giving a detailed account of a method pursued by him in founding stereotype plates. The process resembled Stanhope's method considerably, possessing, however, greater simplicity in its arrangements. Other contemporary inventors were APPLEGATH and BRUNELS.

The Stanhope new and practical process of stereotyping, as well as stereotyping in general found a very divided reception. A serious drawback to the use of these first stereo-type plates was their want of uniformity in thickness, which caused both labor and vexation in the printing; this and other minor defects disposed many of the old-fashioned pressmen to set their faces against the innovation. By some stereo-typing was bitterly contested, by others lauded to the skies. In 1807, the April number of the "Monthly Magazine" (London) attacked stereotyping in the following terms:

"Stereotype printing has not been adopted by the book-sellers of London, because it does not appear that more than 20 or 30 works would warrant the expense of being cast in solid pages; consequently the cost of the preliminary arrangements would greatly exceed the advantages to be attained.

On a calculation, it has appeared to be less expensive to keep certain works standing in movable types, in which successive editions can be improved to any degree, than to provide the means for casting the same works in solid pages, which afterwards admit of little or no revision. As the extra expense of stereotyping is in all works equal to the expense of 750 copies, it is obvious that this art is not applicable to new books, the sale of which cannot be ascertained. Altho these considerations have induced the publishers of London not to prefer this art in their respective businesses, yet it has been adopted by the Universities of Cambridge and Oxford; and from the former some very beautiful editions of Common Prayer Books have been issued to the public; probably the art of stereotyping applies with greater advantage to staple works of such great and constant sale, as prayer-books and bibles, than any other." This very disparaging statement was hotly contested by Mr. Wilson, Lord Stanhope's partner, in a lengthy article addressed to the London book-sellers and printers.

Even after plaster of Paris stereotyping had been practiced on a relatively modest scale for almost twenty years, the opposition against the art had not yet abated.

Hansard, the celebrated London printer and writer on printing subjects, wrote in the year 1825: "No printer should stereotype who wishes his type to be a credit to his house. The wear of material in casting is miserable, the gypsum is at best a fine powder, and grinds away the edge and face of the letter when rubbed in with a brush, in a frightful manner. The letter can never be entirely freed from the plaster, and will present a very dirty appearance ever after."

Equally bitter in his condemnation of stereotyping was Johnson, printer and author of a celebrated book, entitled "Typographia" (1824). In this two volume work, Johnson devotes but a few meager lines to the subject of stereotyping. He writes: "We conceive that the inventor of stereotyping is not worth the pains of our tracing; and more particularly when we reflect that so many of our brethren who well deserve (from their ability) a comfortable subsistence, and who ought to be enabled (from their profession) to move in a respectable sphere of life, are now through this process, reduced to a very humble pittance; thereby bringing the first art in the world down to the level of the lowest; and, at one season of the year, nearly one-half of the valuable body of men alluded to may be considered as destitute of employ on account of the standard works, which was the summer's stock work."

The plates made by the Stanhope plaster of Paris process were of wonderful depth, sharply cut and gave the very best impressions. There were, however, in the practical use of the plaster process many inconveniencing manipulations; the method is a slow one, causing great loss of time. The type becomes dirty, small specks of plaster adhere to them and necessitate cleaning before re-distribution of types. The sheet is smudged through the high spaces that are necessary with plaster casting. The most important drawback is that from the plaster matrix only one cast can be made.

All of the above cited inconveniences, drawbacks and criticisms of the plaster of Paris method of stereotyping led members of the trade to further experiments and advance in the art, the ultimate aim being to devise a stereotyping process which would eliminate these drawbacks and to make stereotyping simpler, cheaper and more practicable.



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