The first load being built straight up and flat on top forms a firm and
secure base on which to build the upper structure.
Laying out or putting in the bulge is the most important part of the
stack, for it contains the greater part of the grain; by laying out and
keeping the stack _flat_, the work can be done rapidly, and when the
stack settles the buts will hang down, for there is nothing to hold them
up.
Filling the middle corresponds to putting rafters on a building to
support the roof.