"micky" wrote in message
...

When a quality cement/sidewalk pourer puts a sidewalk in, does he make a
real effort to have the ground underneath flat and horizontal?

Not exactly. Paved or poured sidewalks do not lie directly on the
ground underneath. The contractor has to prepare a foundation
for the sidewalk, usually done by digging out the dirt and replacing
it by gravel of a planned size (to enable drainage, to prevent the
sidewalk's cracking in future years etc.) which must be tamped
down and levelled before paving or pouring.
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)