A Chapter on Foundations. 289 



of the staging. The second course composed of two or more 

 stone is then built upon the first and set in mortar and clamped 

 and doweled together. The screws are then slacked down until 

 the top of the course is level with the staging, and so continue 

 ■until the' work reaches bottom. The several piers are then con.- 

 nected by iron beams and brick arches covered with concrete, the 

 surface may be paved with any suitable material. I can state 

 from my own experience that such piers have been built in from. 

 12 to 20 feet of water without the least difficulty. 



Gren'l Richard Delafield's memoir on foundations in compress- 

 ible soils is probably the ablest investigation on the subject. 

 19 



