646 NEW YORK STATE MUSEUM 



Mixed colors are commonly prodticed by the addition of some 

 metallic oxid, such, as manganese, or a ferruginons shale, to a 

 light burning clay. The addition of finely powdered manganese 

 oxid to a buff burning clay produces a gray color. 



Speckled bricks are obtained by adding the manganese in a 

 finely granular condition. 



Mottled bricks. In these the manganese is added in larger parti- 

 cles. Ferruginous shale is sometimes employed, and pyrite has also 

 produced the same appearance. 



These manganese brick are used to an enormous extent at the 

 present day. On account of their mottled appearance and rough 

 surface they are considered by many to produce a much softer 

 appearance and richer color than the plain pressed brick. 



Roman tile or Pompeian brick. So called on account of size and 

 shape, in which they are similar to those used in Eoman times. 

 Their dimensions are 12x4x1^ inches. They are made either plain 

 or speckled, and either dry pressed or of stiff muds. 



Norman tile. These differ from the preceding simply in being 2 

 instead of li inches thick. 



Ornamental brick include all those of irregular or fancy shape. 

 Their chief use is for cornices, sills, panels, etc., and they are made , 

 in the same shades and colors as the ordinary forms of pressed 

 brick. By reason of their elaborate form they often command 

 high prices, and $50-$60 a thousand is not uncommonly de- 

 manded. 



Flashed brick. On some pressed brick one edge shows a darkened 

 and slightly fused appearance, brought about by setting the brick 

 with this edge exposed, and then causing a reducing action in the 

 kiln near the end of the burning, by shutting off as much air from 

 the fires as possible. 



The number of ornamental shapes produced runs up into the 

 hundreds, and many manufacturers carry a ve^ry large number in 

 stock. 



