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AMERICAN FORESTRY 



not excessive. This class is more generally known as 

 "Semi-Mill Construction." 



Each of these types is provided with a lighter top 

 floor to take the wear and give a finished surface. 



Nearly all important cities have large and handsome 

 buildings of this kind, where wood is giving as good 

 service as steel would give and at a much lower cost. 



One of the distinctive purposes of mill construction 

 is to obtain strength and stiffness with a minimum 

 amount of timber surface and corners exposed to attack 

 by fire. Large supporting members and flat, smooth, 

 heavy floors provide this requirement. Large timbers 

 do not ignite readily, and if exposed to fire burn slowly 

 and with but a slight penetration after a considerable 

 period of time. Flat, smooth surfaces possess this same 



strength, usefulness, and beauty. If a fire does occur, 

 the large beams and posts burn slowly and they never 

 collapse until they are burned through. In that particular 

 they are superior to steel beams which heat quickly and 

 then buckle, bringing down in ruins everything above. 

 The objection to wood because it is susceptible to 

 decay has been overcome to a considerable extent, so 

 far as the use of this material in buildings is concerned. 

 So long as it is kept dry, it will not decay. It is not 

 always possible to keep it dry, but the intelligent builder 

 sees to it that his wood is exposed to the elements no 

 more than is necessary. The knowledge and practice of 

 treating timbers with chemical to hinder or retard rot- 

 ting have progressed so far that wood exposed to damp- 

 ness may be made to last a long period. So far as build- 



BILLY SUNDAY'S CHICAGO TABERNACLE 



The accompanying cut represents the wooden building erected in Chicago for Billy Sunday's meetings. It is said to be the largest wooden struc- 

 ture in the world, 600.000 feet of pine having been used in building it. The edifice is meant to be only temporary, and the lumber was not 

 dressed. The floor has an area of two acres. 



resistance to combustion, and may be reached readily 

 with water from sprinklers or hose. 



The resistance to fire which woodwork of this kind 

 offers is remarkable. The architect plans to have as few 

 corners and hidden places as possible in which fire can 

 gain a footing and burn where it is out of reach of the 

 fire department. To that end, small timbers are not 

 much used, nor are they in favor. A few large beams 

 and posts take the place of many small ones, lessening 

 the fire peril and detracting nothing from the building's 



ings are concerned, the most troublesome decay is that 

 known as dry rot, which does its worst work beneath 

 floors and behind the points of junction of heavy timbers 

 where it cannot be readily discovered. The first visible 

 notice of its presence may be the collapse of a beam or a 

 floor. Good ventilation is the preventive and cure for 

 dry rot. Its name indicates that it is active in dry situa- 

 tions, and the popular notion is that its destructive 

 activity is in some way due to dryness, and that in that 

 characteristic it differs from other kinds of decay which 



