For brick column to be safe, maximum stress in it ( due to self weight) should be less than breaking stress.
For limiting case, we can consider maximum height be H of the column, for which stress reaches breaking stress (limiting value).
P0+ρgH=σB
105+1.8×103×10H=3.7×106
1.8×104H=(3.7−0.1)106
1.8×104H=3.6×106
H=200 m