Show A fireproof joist professor goodman GoodmanN lt by ali tin ia builder us stating in ili a lecture on oil tire iro prevention that generally nene rally speaking wooden jodts joists are better for buildings thau than steel or tron iron joists foists the two litter latter materials be explained lose their strength at a not very high tempe temperature whereas he Teas wood would su sustain a beaty forasmuch fora for a much longer period when exposed to ficat heat ee be izes when wood h has lq once been charred it does doca not buru burn so EO readily again iron and steel soon eap exp ind under the influence of beat brick anck and stone nio ate objectionable the fornier becomes fused undergo cat leat bett aud ami I 1 le ho i itter Is I 1 liable to crack or lly fly when suddenly cooled after heating hep tins the draw back to tiles I 1 u that when fire payi upon tipon the joists foists of floors floora fitted with them the joints joists expand and allow the fire to play upon the fists joists through th the tiles portland d cement is objectionable object I 1 0 liable ri as r i it I 1 t lakes flakes oft off when r han licit heated ted lint but if wire netting or bars are in fit concrete this defect is reine remedied died A joist padded with silicate of otton cotton c and intended inc inte ineil nied in 10 salamander plaster U a mixture of hi licato cotton mid and plaster of pins pari the professor isor holds ho ils Is a splendid ig ia mit crial erial stich a isi is not lot only nonconductor but it ii ht elastic and 1 I would yield will the joist in na an ex reri regiment ment undertaken by professor good man mail it was found that a joist 0 of shii kini kind withstood ver fierce heat for ci right ht to nginr bours boura without dam ase |