Dig your foundation for your fireplace and chimney at least three feet
deep; then fill the hole up with small cobblestones or broken bluestone
until you have reached nearly the level of the ground; upon this you can
begin to lay your hearth and chimney foundation. If you fail to dig this
foundation the frost will work the ground under your chimney and the
chimney will work with the ground, causing it either to upset or to tilt
to one side or the other and spoil the looks of your house, even if it
does not put your fireplace out of commission.