708 GEOLOGY OF OHIO. 
These tile, as fast as cut, are piled in close order on a ear standing beside 
the machine ; when the car is piled two deep, all over, it is replaced by 
an empty one and is run upon another car whose track lies beneath the 
general level, and whose top just reaches the floor. The two cars are 
at right angles. ‘The lower carriage runs past a succession of parallel 
tracks, all at right angles to its line of direction. At any track the 
lower carriage can be stopped and the upper run off on either side. The 
wings of the building are filled with this system of tracks, and, when 
working, the space is filled in succession with cars of green tile. 
When dry, this is run out and by a continuation of the same system of 
tracks run down to the kilns and finally into them, so that ware made 
at the machine is put upon the car, from which it does not move until 
set for burning. These tracks run further into the yards and are used 
to draw the kiln as well as to set it. Hmpties are brought around by 
a switch to the machine. The whole system is most complete and 
seemingly economical, and though imperfectly sketched here, the plan 
can be seen and adapted to any case necessary. The factory produces 
several grades of tile which are used just like stone or large bricks, and 
are capable of fairly good service in that line, though any unevenness in 
burning makes a disagreeable variation of color in the ware, and also 
the soft plastic clays used allow considerable chance for shrinkage and 
warping that would be avoided if the tile were subjected to more 
pressure or made of a stiffer clay. 
EIRE-PROOFING. 
This is a technical name for a peculiar kind of hollow-tile, designed 
to encase the iron beams and girders now so much used in the construction 
of large city buildings and factories. The beams are of a peculiar 
shape, and the tile have to be accurately fitted to them to serve the pur- 
pose well; when finished, a beam is separated from all outside sources of 
fire by a double wall of tire-clay and an air-space between. The tile is 
simply and easily made on an “auger” machine with adjustable dies, 
and offers no peculiar features in ifs manufacture. It is burned just 
hard enough to cease shrinking and to expel the water from the clay ; 
where it is most largely produced it is made from the sandy clays used 
for sewer-pipe. The two largest sources of fire-proofing are Messrs. J. 
Francy & Sons, at Toronto, Jefferson county: and the Wassall Fire 
Clay. Co., of Columbus. : : 
