FIRE-PROOF BUILDINGS. Tih 



" Iron is not fire-proof. It is, in fact, a combustible, and with heat enough 

 not only bends and yields, but actually burns up. It resists a moderate heat, 

 and when partly covered by brick arches, exposing only the lower edge, it will 

 stand for some ti i e. But in such fires as break out in the great manufactories 

 and warehouses of London, New York, Chicago, and Philadelphia, where large 

 quantities of inflammable goods are piled beneath ceilings, supported on rolled 

 iron beams, they yield, and, in falling, ruin all floors below. If protected by 

 thick plaster upon wire cloth or netting, or by tiles so moulded as to cover the 

 lower side of the lower flange, they will stand longer; but even then I doubt 

 their safety in great fires. Cast and wrought iron in the form of story-posts or 

 pillars also quickly yields to the heat of these great and fierce conflagrations. No 

 stone, unless of horizontal section, covering more floor space than can be ordina- 

 rily spared, will safely resist these fires, and when iron or stone yields it yields 

 suddenly and disastrously. A more unsafe staircase than one of slate upon 

 wrought-iron beams can hardly be made. Slate explodes under a moderate heat 

 like granite, but with greater violence. I have seen the occupants of a new log 

 hut in Lookout Valley driven out of it by the flying slate of the walls of its chim- 

 ney and open fire-place. 



"Brick is the only real fire-proof material available at reasonable commer- 

 cial cost, and it should be used in masses of considerable thickness to be safe. 

 Light square pillars will not stand. Piers of some thickness and of considerable 

 horizontal length will long resist fire. The safest story-post — /. e., a post sup- 

 porting a floor at reasonable cost — is one of some hard and not resinous timber. 

 Posts of oak, of fourteen inches square, will stand safely through almost any fire, 

 until the powerful force and means of our city departments are able to quench the 

 fire. If wrapped with wire netting, covered afterward with plaster, they will 

 suffer still less; but the naked wooden post will remain cool and strong in its cen- 

 tre for hours, and the fire will not for a long time char it to a depth sufficient to 

 much injure its strength." 



With regard to fire-proof floorings, we cannot do better than quote from the 

 same letter, wherein a number of excellent suggestions are given on this subject : 

 " A not very costly and a very fire-resisting floor is described in the old books on 

 carpentry. It is in a room sixty feet square in Amsterdam. It is built of three 

 thicknesses of one and-a-half-inch plank, tongued and grooved, well nailed and 

 laid crossing each other at different angles. The edges of the floor rest on offsets 

 all around the walls. It is reported as very stiff and strong. Air would circu- 

 late but slowly through such a floor, and if between the two lower layers of plank 

 a course of felt or of strong paper were laid, all such circulation would be cutoff. 

 Even this floor would be safer — /. e., it would resist fire longer — if it was plas- 

 tered on wire netting on the under side. A good floor can be made on the plan 

 so well advocated by Mr. Edward Atkinson, with one or two layers of thick 

 plank tongued and grooved or spliued, resting on stout beams eight to twelve 

 inches wide and of depth to give the necessary strength. For this floor he recom- 

 mends a course of plastering on wire netting, inclosing the beams and following 



