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THE POPULAR SCIENCE MONTHLY 



through intense heat in their process of manufacture. The internal 

 framing, the skeleton, is of steel, thoroughly jDrotected from fire by 

 brick or hollow tile; the partitions and floors are also of tile; the ele- 

 vators and stairways are enclosed and witli automatically closing doors 

 at every story so that each story is a unit l)y itself, virtually*a separate 



FutE's Ingress via the Window Route. 



building. This is all-important. Fire's tendency is ever upward. 

 Make it impossible for fire to travel from story to story and you have 

 cut down your fire possibilities 90 per cent. And the same thing ap- 

 plies to each story. These should be so partitioned as to form as small 



