23 



and columns are true, plumb, and thoroughly braced. 

 See that spacing, width and depth are accurate. Never 

 trust too much to memory. Carry blue prints with you 

 in checking up. 



It is very poor policy to let any centering stand in 

 a hot sun an hour longer than is necessary. Plan the 

 placing of steel and concrete accordingly. 



When wrecking it will be found very convenient to 

 'ise two tall horses under a floor panel. They may be 

 built of comparatively light stuff and so be portable, 

 and can be designed in a number of ways. The main 





FIG. 7. SKETCH OF DOUBLE STEP-LADDER OR HORSE 

 USED IN REMOVING CENTER I NC,. 



thing is to combine the idea of a ladder or possibly 

 two ladders facing each other on each horse, with that 

 of a horse onto which to lower the longer stuff as it 

 comes down, then lower to the floor and remove. 



Never let any foreman remove centering without in- 

 structions. 



