Snapping vertices to faces

Hi there,
I’m trying to place a sphere exactly on top of a column. How do I snap the bottom vertex of the sphere to the centre of the top face of the column?
Thanks!
Bryony

A simple way would be to put the 3D cursor at the centre of circle (shift s), then move the globe to the 3D cursor (shift s). Then using snapping to vertex and moving on the y axis move the cylinder up to the right height.