Journal of the Society of Arts 267, 1.1.1857
BOLTON. - On Wednesday the 16th December, a lecture on "Stained Glass Windows," was given by Mr. G. J. French, president of the Mechanics Institute. The lecturer glanced at the traditional account of the discovery of the formation of glass by certain Eastern merchants, after cooking their victuals on a sea shore. The two materials which, when fused together, formed glass, were fine sand and an alkali or alkaline earth, as potash, soda, or lime. If these were perfectly pure and free from other substances, the result would be a colourless glass, but impurities always mixed with the sand, as iron, copper, or lead, not visible tothe eye, but being combined with the substance used, the metal had the effect of colouring the glass; impurities in the alkali had the same effect. The commonest glass, that used for bottles, was of a dull green colour, arising from the presence of iron rust in the sand and dirt in the ashes from which it was made. The white or colourless glas was a most valuable product, to which we were indebted for one of the greatest conveniences of civilisation. To make coloured glass it was requisite to mix in the melting pot some metal with the ingredients before mentioned. The coloured glass thus produced was called pot metal, or pot metal glass, which was blown in circular pieces or tables, similar to common window glass, and sometimes cast in plates. Mr. French exhibited specimens of this glass; the purple or ruby pot, red, yellow, blue, green, violet, and black - and named the ingredients from which they were produced. In different proportions the ingredients produced various tints of colour; they were also altered by the greater or less amount of heat to which they were exposed in the melting pot. A specimen of "ruby flashed" glass was shown, and the operation of forming it described. The lecturer the noticed the mysterious recipes which so recently as 50 years ago used to be published about the modes of making the coloured pot metal; it suited the makers at that time to cover their operations with a shroud of secresy. Most of the best discoveries in the art had been quite accidental; the ancient red glass was coloured by using gold in the pot, yet it was accidentally discovered, in a German glass-house, that a beautiful red might be procured from copper, and this was now done. Much stained glass had been imported into England during the last fifteen years, mostly from Munich, where it was largely manufactured. The colorus were always very dark, with a great preponderance of blue. This glass was by no means pleasing, [---] a very low station in art; but it had been [---] purchased, for no other reason than the depth and fullness of its colour. It must not be confounded with glass made at the Royal Factory of Munich, very little of which reached this country; it was of the very highest excellence in art, and differed in every respect from the manufactured glass described. The existing mode of blowing ruby glass was very old, perhaps as old as the introduction of any glass into this country, which is said to have been England for a long time after that period. Other colours could be treated in the same way as the ruby; such was the case with blue, but this was not done until the beginning of the 16th century, about the tme that Henry the 8th came to the throne. The beautiful purpkle glass and its modes of production were next described. The existing mode of blowing ruby glass was very old, perhaps as old as the introduction of any glass into this country, which is said to have been in the year 647; though there was little of it used in England for a long time after that period. Other colours could be treated in the same way as the ruby; such was the case with blue, but this was not done until the beginning of the 16th century, about the time that Henry the 8th came to the throne. The beautiful purple glass and its modes of production were next described. It was often said that the modern glass painters could not produce the rich ruby colour of the ancient masters; this was a mistake; there was no difficulty in its production at the present day - but the cost of the powder (a compound containing much gold) by which it was produced, caused the modern to use less expensive materials, except for first-rate work. With reference to the term "stained glass," it must be remembered that the only stain that could be given to glass was a yellow one, that was the only colour which could be applied to glass as a stain upon its surface, for the colour in the pot metal and the flashed glass entered into actual combination with the melted materials. The production of the yellow stain was then described, and specimens shown. This yellow stain was unknown before the beginning of the 14th century, about the time of Edward I., and had ever since been much used in preference to the yellow pot metal. It possessed this great advantage, that while all other colours were diffused over the entire piece of pot metal glass, yellow could be applied partially. White glass might be ornamented a yellow device; a yellow stain applied to each side of white glass produced a very rich colour; it might be applied to blue flashed glass, making it green, or to ruby, which is turned into a bright scarlet. Thus the yellow stain added greatly to the resources of the ancient glass painters. The lecturer then dwelt for a short time upon the materials which the glass painter does not or should not employ. The most imperishable materials should be used. Oil paint or varnish, even in small quantities, would prove at length a cheat and a delusion. He had more than once detected this fraud in expensive windows. Having described the materials for making a window, he asked their attention to a brief history of the art, the mode of executing the work, and the tools employed at various times. He would begin with what was called the Norman style of church architecture, commencing about the year 1066, and which continued until the year 1,200, a period of 134 years. The walls were remarkably thick and deeply splayed inside, and the windows very small and narrow, with rounded tops. The obvious intention of this arrangement was to admit as much light and to exclude as muc bad weather as possible, and the inference to be drawn from this arrangement was that no glass whatever was used in such a window. The height also served to protect the people from wind and rain. Very little light could be supplied by these windows. The chancel, where the services were read, was usually better lighted with three windows of the same kind placed close together. Long before this time, however, glass windows had been occasionally used in churches, but no vestige of any glass of the Norman period had been discovered. With the early English style, which succeede the Norman about 1200, and remained in fashion about 80 years, much more light was let into the church; the windows were longer and larger, often placed two, three, or five together, always with pointed tops, like a surgeon's lancet, hence called lancet-shaped windows. The early English was succeeded by what was called the decorated style of Gothic. The opening of the window was not much larger than before, and the head was often beautifully filled in with flowing and geometrical tracery. This style prevailed from 1280 to 1380 just one hundred years, when the first three Edwards reigned. The last style of Gothic architecture was called the perpendicular, because the principal mullions in the window, instead of diverging when they arrived at the spring of the arch, as in the decorated, ran straight up to the top, though delicate tracery was introduced between them. The perpendicular stuyle lasted from 1380 to 1530, or from the time of King Richard II. to Henry VIII. inclusive. No glass of the earliest or Norman style has been found in this country. It was profitable that ordinary churches had none. Of the early English style, many examples remained. During the early English period a great change took place in the style of glass painting [---] white glass of a beaufitully translucent but not transparent kind, was largely employed; this was arranged in graceful patters, the lead work flowing in finely curved lines, a very slight proportion of coloured glass being introduced in samll medallions and other graceful forms. The finest example of this kind of glass which he had ever met with was in the windows called the Five Sisters, in York Minster. The lecturer then exhibited some fine specimens of old glass of the period treated [---] . The specimens were proved to be above 500 years old by the absence of the yellow stain. He also exhibited some ancient specimens of Frenc painted glass, proved to be before the time of our Edward III. The process of producing these was minutely pointed out. Mr. French then gave an elaborate description, aided by a coloured engraving, of the great east window of York Minster. John Thornton, of Coventry, contracted with the dean and chapter of York to glaze the window in the space of three years, drawing the figures and ornaments and painting the glass himself. The materials and such assistants as he required were provided by the dean and chapter, who also agreed to pay him as wages every week 4s., at the end of each of the three years £5, and after the work was completed £10 more for his reward. The windows of St. Stephen's Chapel, Westminster, were executed under the cahrge of one John de Chester; that is of an artist named John, a native of Chester. He had 7s. a week for wages, and employed other workmen [---] 6d. a day, among whom was a John de Coventry, probably the father or grandfather of that John Thornton of Coventry, who, fifty years afterwards, commenced the York window. The ancient process was quaintly pointed out, and the tools of the old workmen described. The croyscur, or cross iron, was one of the tools, and John de Chester was i nthe habit of paying to simon le Smyth 1½d. each for them, "and bought as many as seven at a time." Now and then events of local historical interest were found recorded in tained glass, and when such had been preserved they were always of great value. Mr. French here showed an accurate coloured tracing on glass now in the Parish Church of Middleton, the adjoining parish to Bolton. He believed the glass was not originally placed there, but was long ago removed to the church from an old hall in the neighbourhood. It represented a priest and 16 archers kneeling in church, and saying a prayer of thanksgiving for their safe return from the bloody battle of Flodden Field, to which they were led, under the command of Edward Stanley, in the year 1513. Each archer carried his bow over his shoulder, [---] quiver of arrows at his side, and had his name insrcibed over his head. Most of the names were represented by families still resident in and about Middleton. They sometimes, great difficulty of supporting the large painted windows, and yet shading the iron and leads required, was next pointed out and examples given. For the production of a workd of high art in stained glass; a combination of qualifications was required. Supposing that the artist was at liberty to choose his own subject, he should so treat it as to harmonize with the sacred character as well as the architectural decoration of the building in which it was to be oplaced; there should be solem repose in the figues, and, as far as possible, no appearance in action. The colours also should please by their harmonious arrangement, rather than surprise and startle by brilliancy of contrast. There were great difficulties in the way of high art in stained glass, though he hoped they were gradually giving way before increasing demand and greater skill. Heraldic subjects were largely used in painted glass. Mr. french then exhibited numerous specimens of old coloured glass, explaining the curious devices with which some of them were ornamented. He then referred to some of the modeern improvements introduced into the manufacture, observing that the invention of moulding gad been applied in many ways for the purpose of adorning windows, as in a specimen which he exhibited, where the centre was a rich Lancashire rose, which was not cast, as might at first be supposed, from ruby glass. The rose was white glass, but there was placed over it a very thinly blown plate of ruby, which imparted the colour to it; had the rose been cast in ruby glass, it would, from its thickness show almost black. The three-light window over the communion-table in Christ Church, Bolton-moor, was for the most part filled with moulded glass, and was well worth attention. There could be no doubt that the modern artist and manufacturer would be enabled to introduce numerous effects from the employment of cut crystal and moulded glass far surpassing in gorgeous splendour the utmost efforts of the old masters. At the conclusion of the lecture a vote of thanks was warmly and unanimously accorded to Mr. French.