Mr Fairbairn on Fireproof Warehouses. 105 
heat melting the columns, in the event of fire, in any of the 
rooms, a current of cold air be introduced into the hollow of 
the columns from an arched tunnel under the floors. 
Adopting the foregoing divisions of the subject, it will be 
requisite to consider them separately. 
First, The whole of the building to be composed of non- 
combustible material, such as iron, stone, or brick. 
In the choice of material, much will depend upon locality, 
and the cheapness at which it can be obtained. In this 
country the best fireproof buildings are generally composed 
of brick or stone, with iron beams and columns properly 
framed and held together by rods built into the walls, and 
brick arches for the floors: these arches are supported by 
and spring from the lower flanges of each beam, and are 
thus extended in succession on each floor from one end of 
the building to the other. These arches may be formed 
either in a longitudinal direction in the line of the building, 
or transversely, as circumstances may admit. The floors 
are generally laid with stone flags or tiles upon the arches, 
after they are properly levelled and filled up at the haunches 
with a concrete of lime, sand, and ashes. The flags or tiles, 
being well and solidly bedded in mortar, form a durable and 
excellent floor. In buildings for particular objects, it is some- 
times necessary to have wooden floors, and, where found 
necessary, the boards are generally nailed in the usual way 
to sleepers embedded in the lime-concrete as before de- 
scribed, or, what is probably better, with a pavement of wooden 
blocks. 
This description of building, when properly constructed 
and surmounted by an iron roof, is perfectly impervious to 
the action of fire; and provided due regard be paid to the 
selection of a careful superintendent, both owners and occu- 
pants may rest satisfied as to the safety of the property. 
Secondly, In order to prevent fire, whether arising from 
accident or spontaneous combustion, every opening or cre- 
vice communicating with the external atmosphere to be 
closed. 
These are points which should never be neglected in fire- 
proof buildings. In warehouses, in particular, it is of vital 
