History: In the late 1880s, Architect/Engineer
Gustave Falconnier [1845-1913] of Nyon, Switzerland, invented a novel
form of glass building block or "glass brick" (German glasbausteine,
French brique de verre). Falconnier's bricks were hollow, blown in
mold (BIM), and had the original feature of being sealed air-tight with a
pastille of molten glass while hot; after cooling, the hot air trapped
inside contracts, forming a partial vacuum.
Unsealed hollow glass blocks by Deutsche Luxfer Prismen-Gesellschaft
|Earlier glass bricks such as those by Siemens and Deutsche Luxfer
Prismen-Gesellschaft were unsealed and shaped like traditional masonry
bricks (but without a bottom surface); they had problems with
condensation and dust collection on their interior surfaces.
Unsealed hollow glass blocks by Siemens of Dresden
Briques were manufactured by Albert Gerrer of Mulhouse (Haut-Rhin),
S. Reich & Co. of Vienna and others. Their sides were recessed to
take mortar and they were laid up like ordinary masonry bricks, with or
without metal reinforcing embedded in the mortar. Falconnier's hollow,
air-tight design, a prize-winner at the
1893 Chicago World's Fair and
1900 Paris Exposition, had several advantages:
"By making such bricks or blocks hollow, especially when they are
made air-tight, they possess several advantages over other materials,
being cheap, light, durable, and ornamental. Further, by reason of
their inclosing and confining air in a state of rest they serve as
non-conductors of heat."
—US Patent No. 402,073
Haywards Ltd. bought the patent and marketed
them in England for vault and window walls. Despite initial interest
from important period architects such as
Auguste Perret and
Le Corbusier, and some
(La Mission d'Algérie,
house of Mumm,
etc), Falconnier's design was apparently not a great commercial success. The
bricks are rare today, and existing installations even rarer. They suffered
from the same defect as early vault lights: damaged glass could not easily be
replaced. Falconnier briques are sometimes mistaken for fishing net floats.
Markings: All Falconnier bricks are marked
with embossing, usually "FALCONNIER / DEP FRANCE
BELGIQUE + nnn / FRANCE" where nnn is the style
number, most commonly 8. Bricks produced at other factories have different
markings, but they all proclaim "FALCONNIER".
|Partial bricks: For finishing square openings,
each brick was also made in ¾, ½
and ¼ sizes. A ¾ brick finished the long side, a ½
brick finished the short side, and a ¼ brick finished a corner.
Colors: Most bricks were light aqua, the usual
color of glass made from sand with iron contamination (which is most sands,
as any child who's played in a sandbox with a magnet can attest), but other
colors were available at extra cost:
clear for improved light transmission, and
decorative colors amber, green, blue and
(opal) milkglass (all colored in the mass). A red brick was made by casing
a clear brick in a thin layer of expensive, gold-based ruby glass. The
patent mentions coloring "either in the mass or by coating or covering
them inside or outside in full or in part with layers of metal or paint",
Additional ornamentation by sand-blasting, cutting and engraving, or acid
etching is also mentioned, but I have yet to see these variations.
Value: Despite rarity, prices are low since
there are very few collectors of early glass bricks (basically: me),
so there is little demand. The most common brick, the #8 in light aqua, is
difficult to sell at any price. I have seen hundreds for sale (often in
large lots), and would price them at about US$5. Rarer patterns and colors
are worth more, as are partial bricks. The high end is about US$150.
Finis: Modern-style two-part fused glass
blocks were perfected in the 1930s, more than forty years after Falconnier's
bricks were introduced. Around the same time, Belgian company
Etablissements Gaston Blanpain-Massonet of Bruxelles was still
producing bricks in the #8 pattern (always the most popular) as seen in
this catalog page, as well as the glass bricks
of style Glasfabriek Leerdam.
Nyon: See this article on Falconnier by
the City of Nyon Archivists for more about his history, and additional photos:
La brique de verre Falconnier.