Arthur Korn’s “Glass in Modern Architecture” (1928)
Translated from the German by Dennis Sharp.
(Barrie & Jenkins. New York, NY: 1968).
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Introduction to the First Edition
Glass is an extraordinary material. It gave us the beauty of medieval stained glass windows. Tightly held between supporting piers they opened a door to allow a glimpse of paradise in luminous colors from the shadow of the grave.
Nothing has been lost from the richness of those earlier creations, but glass has now been associated with other materials to meet new functions. A new glass age has begun, which is equal in beauty to the old one of Gothic windows.
Up to the present time glass has been a secondary building material, which remained subservient in spite of all its intrinsic ornamental strength, in spite of its crucial position in the interplay of structural forces, in spite of its underlining contrast with the masonry of the walls. The contribution of the present age is that it is now possible to have an independent wall of glass, a skin of glass around a building; no longer a solid wall with windows. Even though the window might be the dominant part — this window is the wall itself, or in other words, this wall is itself the window. And with this we have come to a turning point. It is something quite new compared to the achievements through the centuries…it is the disappearance of the outside wall — the wall, which for thousands of years had to be made of solid materials, such as stone or timber or clay products. But in the situation now, the outside wall is no longer the first impression one gets of a building. It is the interior, the spaces in depth and the structural frame which delineates them, that one begins to notice through the glass wall. This wall barely visible, and can only be seen when there are reflected lights, distortions or mirror effects.
Thus the peculiar characteristic of glass as compared to all materials hitherto in use becomes apparent: glass is noticeable yet not quite visible. It is the great membrane, full of mystery, delicate yet tough. It can enclose and open up spaces in more than one direction. Its peculiar advantage is in the diversity of the impression it creates. Only in recent years has it been realized that this material opens quite a new range of possibilities to the architect. A few examples may illustrate what I mean. If we take, for example, the Bauhaus in Dessau by Walter Gropius, or the buildings by Mies van der Rohe, or the design for the Kopp & Joseph shop by Arthur Korn, we notice quite different aims behind the use of glass.
1) In the office block by Mies van der Rohe (p. 12) and the workshop at Dessau (p. 17) the visible depth behind the thin skin of glass is the exciting factor.
2) In the curved office block by Mies van der Rohe (p. 10), the strength of the outer skin with its reflections and mirror effects, as well as the curvature of the smooth glass surface as such, is predominant.
3) With the Kopp & Joseph shop by Arthur Korn, apart from the spatial articulation, the strong color effects behind an invisible screen are specially emphasized. Here the glass skin is no longer of any visual importance but purely a medium to form a barrier against the weather etc.
When looking at these various possibilities we realize that new rules are at work here, different from those of the past. Glass has an extraordinary quality which enables it to render an outside wall practically non-existent, when one compares such a wall to those made of other materials — stone, wood, metal or marble — all of which form solid barriers.
Obviously, the opening up and perforation of a wall has been an aim and a problem for a considerable time and in some instances solutions were found which even made the interior of a building visible from without, but never before did man succeed in enclosing and dividing up space by a single membrane. It is this membrane which really encloses a building, but only with certain qualities of a solid wall, such as defense against temperature variation and noise, as well as the provision of safety. This is not a purely imaginary wall as it is in the case of the regular rhythm of columns around a classical temple.
It is evident that a material of such qualities requires the building itself to be remodeled, conceived in a revolutionary way. The building by Mies van der Rohe, a structure of unusual and perfect clarity, is based on new and different rules for the use of glass. There is evidence of a new structural concept where all load-bearing elements are kept within the core of the building, leaving the outside wall free to be nothing but a wrapping to enclose and to allow light to penetrate. This function is just the peculiar characteristic of glass, which in this formula shows itself to be at the same time a medium for the penetration of light and a skin for a building, reflecting the sparkling of its own lights and heightening the effect through the occasional glimpses of the load-bearing supports in its interior.
Even if the intensity of color effects of the new neon lights compete with the strength of those of the old Gothic windows, they are both two-dimensional colored surfaces only. The new characteristic of glass is evident only when it opens up views deep into the inside of the building, thus exploiting its peculiar property through its position. It is only here that it can show in all its purity the strength of this sophisticated, yet in a way simple, characteristic. Compared with this special and individual property, all other effects of glass — colorful, brilliant, and stimulating — are of secondary importance.
The disappearance of the outside wall of a building has its counterpart in a similar process inside. Partitions dissolve into glass walls. This can be observed in various examples, as for instance in the girls’ hostel in Prague by Tyll (p. 50) where one passes glass partition after glass partition and meets the same fullness of light inside as in the street outside. Where solutions like this are also coupled to a process of eliminating as many solid walls as possible in the core of a building, delicate structures emerge such as the house for the co-operative by Le Corbusier (p. 19) or the sanatorium at Hilversum by Duiker (p. 55).
The qualities of the architectural concept which have proved both new and lasting have also been evident in the approach to the designing of shops. Here again the tendency to utilize the two-storey skin effect for visual penetration into depth offered possibilities other than the flatness of former shop windows. Novel developments followed in the area of large-scale advertisements and hoardings in the townscape. Today, it is possible to show these to similar advantage by daylight and during the night with the aid of glass bricks and large sections of sheet glass which can be covered by signs and lettering up to fifty feet high. These large glass surfaces can glow with a diffuse light by night as in the staircase tower in Magdeburg by Carl Krayl (p. 46), where the large signs hardly impede the penetration of daylight. With the help of these large glass surfaces it is now possible to have much greater freedom for advertising designs which hitherto had to be hemmed in between the spandrel panels below window cills.
The window as the structural element of the large glass surface had to be redesigned from basic principles. This was done not only because of the general tendency to reconsider and redesign each of the few basic elements of the modern building, but also because the window is the most exposed element in an outside wall, and furthermore, because a window has to be moveable with a frame as thin as possible. This is the reason why quite a number of new window constructions appeared on the market—both casement and sliding windows. One of these new constructions  is shown in the example by a Swiss architect (Artaria & Schmidt p. 69). With the advance of glass as a building material its use for other purposes also increased. Apart from its extensive use for light fittings, it is being used for the sake of its intrinsic beauty, its hygienic, hard and protective surface in conjunction with furniture of various kinds. The glass table by Marcel Breuer (p. 120) is a good example in this connection. But glass is also used for the manufacture of cooking utensils in the form of fire-proof dishes and other glassware, including intensely refined test tubes and complicated laboratory glass vessels, and these show the wide scope of its use and its form. It is just in these admirable shapes and forms that we see how much we can still expect if one day men are to succeed in extending these creations into the realm and dimension of large buildings with suspended pipes in spirals and glass tubes to take staircases and escalators.
The object of writing this book was to point to new opportunities which are still dormant in glass. The technical details of how these may be put into practice can be left to the experts to put into words.