Is there a method or instrument that can be used to level the top of 4 pillars simultaneously?

Question

Assume that the pillars are at the 4 corners of a square or a parallelogram etc.

Answer 1

use a line level

attach string to the top of each pillar so that opposite corners are connected. use either a circular level in the midpoint of the strings or a pendulum suspendedabove a fixed point equidistant from each pillar. remember to account for the overlap of the strings for finer adjustments if necesary.

or if the area is of sufficiently small size than place a flat object over the pillars and use a circular level in the epicenter.

Answer 2

Yes there is. You need a spinning laser level with 4 rods and 4 receivers.

Answer 3

it's called a builder's transit or sight level