| In
the early 1800s, individual glass blocks were used to provide light
to cellars and ships’ bowels – at first, cut squares
of simple conventional glass, then prism-shaped pressed glass which
allowed light to be dispersed. In order to fix this prismatic glass,
they were fitted into steel frame structures in the form of intermediate
ceilings or skylights which allowed larger surfaces to become translucent.
The invention of reinforced concrete – first used by Monier
in 1867 – and the introduction of glass manufacturing by machine
which started the first Lubber machine in 1903 opened up new perspectives
for glass as a large-scale spatial element. In 1904, Joachim, a
French architect, built the first dome of concrete and glass. In
1907 Freidrich Keppler, founder and head of the Berlin Luxfer-Prismen-Gessellschaft
applied for a patent for solid glass blocks of 4 to 6.5cm thickness,
to be fitted into support structures of reinforced concrete. In
the following year Joachim applied for the French patent, “Le
beton arme translucide”.
The
development of hollow glass blocks for vertical structures, which
offered the advantage of better noise and thermal insulation in
comparison to the solid blocks, took place at about the same time.
In 1902, the “Technical Military Committee” praised
he excellent properties of this new invention.
As early as the 1880s, hexagonal bodies with arched exteriors which
could be composed into honeycomb constructions, were mouth blown
for partition and exterior walls. The hollow glass forms which were
shaped like neckless bottles wre initially worked with mortar in
such a manner that the hollow area was hermetically sealed off against
the outside air. Condensation could however seldom be prevented
completely. These first mouth-blown blocks also suffered from such
production deficiencies as differing wall thicknesses and thin corners.
Soon however, more robust machine-made blocks were
offered by Luxfer-Prismen_Gesellschaft as well as Siemens in Dresden.
Their products consisted mainly of open hollow glass blocks which
resembled the usual bricks in size and form. Albert Gerrer in Mulhouse
was at the same time still manufacturing mouth-blown glass blocks
using Falconnier process which however were sealed before the block
cooled down with small glass plugs. Their form still resembled that
of the hexagonal prototypes.
It was not until the 1930s that the further development
of machine production produced more satisfactory types which were
easier to work. The Corning-Steuben block, consisting of two halves
of heat-proof glass pressed together, as well as the Owen-Illinois
block became immediate precursors of the patented block of Pilkington
Bros Ltd (St Helens). Modern glass blocks are still being produced
according to this principle, namely that two moulded glass halves
with a hollow interior are melted and fused together under high
temperatures.
|