24 
EXPOSITION AT VIENNA. 
\/ ^ The earthy group includes faience, terra-cotta, bricks, etc. 
Faience is also a comprehensive term, takiug in all varieties 
of earthenware stoueware, etc., and comprises two chief 
classes, the glazed and the unglazed. The objects may also 
be grouped as hard faience, and soft faience, stoueware 
being an example of the former; but the Classification accord- 
mg to the glaze, or superficial coating, is to be preferred. 
Of glazes, which consist of a composition much more fusible 
than the body of the wäre, there are many varieties. All, 
however, have this in common, that they may become more or 
less fluid in the furuace, and cover the porous surface.of the 
paste or body, giving a vitreous surface when cold. They 
are all more or less siliceous, but the substance giving the 
fusibility may be an alkali, or metallic oxide, usually oxide of 
lead, or of zinc, or oxide of tin. The alkalies and lead give 
a transparent glaze, and oxide oftin gives an opaque glaze or 
enamel, and objects covered with it are described as enamelled. 
A common and cheap method of glazing hard faience is by 
throwing salt into the kiln while the objects are hot. The 
soda combines with the silica'in the wäre, and a vitreous glaze, 
known as salt-glaze, results. 
For this Report an arbitrary grouping is preferred, chiefly 
with a view to conveuience of description. The objects are 
grouped according to their uses rather than by their material 
or manufacture. The faience and porcelains of the principal 
countries are first considered; next, the mural and floor 
tiles, as a distinct and largely represented brauch of ceramic 
industry; third, terra-cotta, bricks, etc. ; and fourth, the 
materials used and their distribution. In cacli of these divis- 
ions there was a profuse representation in the Exposition ; and 
a thorough, critical, and explanatory description would have 
required much more spare and time than have beeil at com- 
mand. In general, only the salient features are touched upon. 
The writerhas, as far as possible, brought prominently forward 
the names of the principal exhibitors, recognizing in this the 
dischargo of a duty to them as well as to the public. Every 
exhibitor at a great exhibition, who makes a display worthy 
of the occasion, does so at no small outlay of time and 
money, and he is justly entitled to all of the advautages