VALUE OF GLASS

Evening Star, Issue 23375, 19 September 1939, Page 3

VALUE OF GLASS

HISTORY THROUGH THE AGES MEAT INFLUENCE OF ARCHITECTURE INTERESTING AND IMPORTANT EVOLUTIONARY STAGES > Glass as a decorative medium in modern architecture is now being widely used in Australia, besides other countries, and also to a lesser (but increasing) degree in New Zealand. In Dunedin, there are several new buildings that employ glass for decorative purposes. This interesting and informative article, which will be continued in next Tuesday’s homebuilder page, traces the development of glass manufacture and its application from the time when its value was becoming recoginsed. The greatest use of glass windows was originally made in churches and probably was at first primarily decorative. The earliest uses were in windows that were closed with marble, but with the marble pierced and small panes of glass fitted in. In medieval churches there is no doubt that the decorative use of glass’ was due to its capacity for taking colour. Glass mosaics were also known at a very early date. The oldest Christian examples now surviving are possibly those at S. Constanza. The barrel-vaulted ceiling of the portico is inlaid with pictures of vintage scenes, cupids, birds, and vine traceries. COLOUR AS A MEDIUM. The coloured glass windows of the Gothic churches certainly were influenced greatly by its eastern prototype. The contact of the Crusader—young men from a continent in a very early stage of civilisation—with the eastern peoples—where the Mahommedan civilisation was mature—had a tremendous effect on the Gothic development. It was not, however, until the eleventh century that much use was made of painted glass as a medium of pictorial decoration. By the middle of the fifteenth century an increased knowledge of chemistry had enlarged the range of colours available to the glass painter, and the art was by then practically complete. As Gothic architecture advanced and windows became more numerous and larger, probably

because the value ot natural lighting "was more fully appreciated, so the area of clear glass increased and the heavier colours were gradually eliminated. Some .very delicate colour work was executed in the latter half of the fifteenth century. IMPORTANT DEVELOPMENTS. There is no record of the employment of glass in domestic buildings in England until the reign of Henry 111., even though it was widely used in churches by that time. The real development of the window in English domestic architecture took place -when the [Tudor period came into being. By that time the price of glass had been reduced to bring it within the reach of domestic builders, and the value of light in a home was acknowledged. The idea of grouping many small units, separated by mullions and transoms, and sometimes extending over two stories in height, became popular. The windows are undoubtedly the most charming feature of Tudor architecture—a style which, by’ its appeal of man’s innate romantic domesticity, is still the most popular for residential architecture. The Renaissance style of architecture reached England coincident with the arrival of French and Italian glassmakers. The combination of these two events had a big effect on window design. It led to the rejection of the mullion for the window of classical proportions. In the banqueting hall at Whitehall the mullion was adapted to classical design. This, of course, was the first developmental step towards its elimination. By the end of the seventeenth century the mullion was completely superseded. In 1685 Inigo Jones removed the original .windows from the banqueting hall and replaced them with sashes. This is the first recorded use of the windows which were to develop into the box-frames, than which no more serviceable window has been invented. MANUFACTURING METHODS. There were then two methods of making glass—cylinder and crown. In the former a ball of glass was gathered on to the end of the blowiron and blown into a sphere. This was elongated by swinging into an irregular cylinder with a domed end. The end was then cut open, widened to the maximum diameter of tfie cylinder and. pinched into the form of a figure eight to form a grip for the punty. The other end was opened up the full diameter as the punty was removed and the figure eight re-opened. The cylinder was then reheated, cut by the shears, and flattened in the furnace. The surface was finally smoothed by a wooden block or an iron rod. In crown a suitable amount of glass was gathered, blown and marvered into a globe. This was transferred to the punty, reheated and spun until the hole left by the removal of the pipe converted the globe into a disc. It was uniform in thickness, except where the punty was attached. This formed the bull’s-eye. The crown was usually superior in to the broad. It was manufactured in Normandy and England, while in the rest of Europe broad was used almost exclusively. Up to the seventeenth cen-j tury there was a belief that decay in glass was caused to some effect by the action of moonbeams, and quite a common clause in contracts was that the glass used to paint on should not be “ crinkled nor spotted nor liable to injury from the moon.” During the Palladian and Georgian periods of English architecture there were very few advances in the use of glass. Both styles, which paralleled each other chronologically, were stiff and formal, and left very little scope for variations in window * design. ORIENTATION IN PLANNING. In tjie middle of the eighteenth century the bay window became a feature of English architecture. It was used in a great variety of forms, including curved and semi-hexagonal bays and oriel windows. This denoted another important step forward in the development of the window. It was not now merely a medium for the admittance of light, but its value in providing a room with an outlook and for purposes of mediation wap being recognised. The repercussions of this were far-reaching, for when these values were realised, the importance of orientation in planning also received consideration. When windows opened up the view, the house was planned to take full advantage of it. Landscape gardening was a direct result of this. And from this, in turn, developed the use of glass in horticulture. The enthusiasm for the garden was responsible for the erection of glasshouses, of which the forcing frames of the Romans were the forerunners.

; Until 1717 the greenhouse was I merely a building resembling a dwell-ing-house with an abundant supply of side windows. Quite frequently the gardener lived in quarters in an upper story over the greenhouse. T]io glass ‘roof was first introduced in 1717, and its value was soon recognised.

(To be concluded.)