THE FIREPROOFING OF CITY BUILDINGS. 589 



\\1ien the furnace had stood sufficiently long for the plastering and 

 mortar to set, tlie girder, being then loaded to one-fourth of its breakinw 

 weight detiected ;5-l(Jths. of an inch. The fire was lighted and kept up for 

 two hours and a half with dry pattern wood as fuel. After one hour the 

 deflection of the girder was -A ths. of an inch in the centre, and at the 

 end of the two and a half hours it had increased to 1 ''.ths. of an inch. 

 Water was then applied through a hose, and when shortly afterwards the 

 upper part of the furnace was removed, the girder appeared uninjured, 

 although the intense lieat had calcined tiie lower surface of the tire-clay, 

 The deflection disappeared as the iron gradually cooled. 



Tiie second experiment was for the purpose of testing the same girder 

 under conditions still more severe, being equal to the largest fire which 

 could exist in any one part of a building. The furnace was rebuilt as at 

 the first and was similarly loaded. The fire was kept up as fiercely as 

 possible for one hour and a half, the flames being continuous. It was then 

 slackened and kept as nearly as possible to a smouldering heat for twenty- 

 four hours, but as the fire had to be renewed from time to time, the heat 

 was periodically increased, and the test thereby made more severe than had 

 been contemplated. The deflection of the girder, which was -i'-ths. of an 

 inch before the fire commenced, became i^nds. at the end of an hour and a 

 half. It increased to a maximum of 1 ^ nds. of an inch, but diminished aa 

 the heat subsided. About an hour after the tire was lighted the plastering 

 began to drop ofi' and four hours later, the fireclay was observed to be 

 red hot. One end of the girder which projected slightly through the brick- 

 work of the furnace was throughout quite cool and no appreciable expansion 

 was observed. At the end of the twenty-foiir hours the fire was put out 

 as before, large quantities of Mater being thrown upon the beam and its 

 surroundings by means of a force pump and hose. The top and side of the 

 furnace was then partially i-emoved, when all the fireclay was found upon 

 the girder precisely as when first put on. The girder which was quite 

 uninjured was subsequently fixed to form part of the flooring of the build- 

 ing to which the experiments had reference." 



Appendix E. 



At the Spirit Room in the Natural History Museum at South Kensington, 

 London, the floor is pierced with iron gratings, and the basement below is 

 laid several feet deep with clean gravel, and the hydrants are placed 

 outside the windows. The flaming spirit and water sinking into the gravel 

 would be extinguished. 



