THE FIUEPROOFING OF CITY UUILDINGS. 579 



12. Coraraunicatioa between subdivided buildings is frequently 

 essential, and the doorways so made are too often the cause of the 

 destruction of large blocks of buildings. Hence, even in slow 

 burning construction they should be as tireproof as possible, and 

 will be described in the next section. 



By the adoption of one or other of the foregoing suggestions 

 best suited to the needs of any particular building, it might be 

 made much less combustible than the ordinary structures which 

 fill our cities, and in most cases a fire could easily bs confined to 

 the particular section of the building in which it commenced, 

 pending the arrival of the Fire Bi-igade. This alone would be a 

 great gain, as a large amount of property would be annually 

 saved, and the distressing loss of life which frequently occurs 

 would be entirely obviated, as .sufficient time would be allowed 

 for escape. The cost of either of these improvements is only 

 moderate, and would not add very appreciably to the outlay on 

 most buildings.* 



The more perfect systems of fire-proofing are of course more 

 expensive than those fir.st described, but are well worth the out- 

 lay in buildings of any importance. I will deal with them in the 

 same order as in the slow burning system. 



a. Cast iron girders and brick arches, (PI. XXX IX , fig. 6), 

 were used for many years in all kinds of buildings, and are still, I 

 believe, in the otton mills of Lancashire, being in that locality 

 the cheapest form of solid floor suitalile for machinery. Cast iron, 

 however, is very liable to blow holes and various other defects, 

 and snaps sudddenly if cold water is thrown on it when heated. 

 This kind of floor is also very heavy and needs to be tied in with 

 rods to resist the thrust of the arches. The serious failure of a 

 floor of this kind at King's College, London, from a defective 

 casting proved the death-blow of this system, so far as its general 

 adoption was concerned. 



h. Fox and Barrett's system, (PI. XXXIX., fig. 7), was also 

 much used at one time. It consists of rolled iron joists supporting 

 small intermediate joists or "]" irons about 1' 6" apart which carry 

 fillets of wood about l^-" x 1^" covered vvith lime-concrete. The 

 wood fillets are a defect, but enable a chea[) concrete to be used, 

 and also afibrd fixing for the ceiling laths. This has lately been 

 obviated by the use of .specially made bricks in lieu of the wood 

 fillets, and so far is an improvement, but nevertheless the .system 

 lacks simplicity. 



i^c. Where a flat ceiling was not required Dennet's arching of 

 plaster concrete, (PI. XXX[X., fig. 8), was frequently adopted, and 

 in Her Majesty's Theatre, Loudon, I have seen this material span- 

 ning 8ft. or 10ft. without intermediate support. Ithas the advantage 

 of largely reducing the quantity of iron in the floor, but the 



* See Appendicea B, and C. 



