A feature of the recent Stuttgart exhibition which attracted considerable attention was a display of buildings which were constructed of what is known as the Falconnier's blown glass brick, so named after the inventor, a French gentleman. The bricks are blown hollow in the same way as a bottle, the color which is most commonly used being a very light bottle green, bottle glass being the strongest; though yellow brown or other shades of green may be used if desired. The standard brick is 5 inches wide, 8 inches long, and 4 inches thick, and is formed in the shape shown in the accompanying illustration. When it is used for walls, or such structures as have to carry a quiet load, the bricks are laid as shown in our view of an ornamental pavilion, and cement is used in the joints, which are hollow. But when the bricks are used in roof work, or where the finished work will be subjected to bending strains, the cement is assisted by winding stout wire around the joint grooves in such a way that it will pass under one brick and over the next, the course of the next wire being reversed. A similar set of wires is wound in the cross direction, so that the bricks are really set in a wire network into which they are securely cemented.

When large walls or arched roofs are made of these bricks it is necessary to make allowance for expansion, especially if the work has been done in cold weather. For this purpose the edges of the bricks are covered with a thin layer of glue, which is subsequently destroyed by the cement between the bricks and leaves sufficient space for their expansion in hot weather.

It is claimed that they are permanently translucent, and that they have the advantage over double glass windows that they do not admit damp or dusty particles, and never tarnish. The surfaces, exterior and interior, are so ribbed and curved that while abundance of light is admitted, it is impossible to see through them. On this account they may be used where an ordinary window would be objectionable, as in the case of a window that looks into those of a neighboring house. Perhaps the most valuable feature of these bricks is that the air which they contain is an excellent non-conductor of heat, and tends to keep a house cool in summer and warm in winter, and, of course, damp will find it difficult to pass through a wall built of this material. On account of its non-conductivity this material is admirably adapted to the construction of greenhouses, and it lends itself to some remarkably picturesque effects in this class of construction, the roofs being built in arched or dome-like forms. It is also used to advantage in the construction of pavilions, such as the one shown in our engraving, or of city restaurants and places of public resort, where light shall be admitted, but a view of the interior shall be impossible.