Heh ..variant?
Small board, perhaps epoxied at ends, middle--a surer-STOP than a mound of $$epoxy
--also for simpler removal later: should Earth (or your slab) tilt a bit off-axis.
(At work I knew a physicist just PhD'd who was famous for having thousands of bizarre 'answers' for problems)
--later went on to Aeroneutronics-Ford IIRC. I visited at his/their new digs in S. CA--and he showed me how he
had landscaped a walkway (of cobble-stones) such that each one's peak was exactly on a plane and the whole
walkway: exactly ⟂ :-þ
[I'm not that Good, obviously]
--also for simpler removal later: should Earth (or your slab) tilt a bit off-axis.
(At work I knew a physicist just PhD'd who was famous for having thousands of bizarre 'answers' for problems)
--later went on to Aeroneutronics-Ford IIRC. I visited at his/their new digs in S. CA--and he showed me how he
had landscaped a walkway (of cobble-stones) such that each one's peak was exactly on a plane and the whole
walkway: exactly ⟂ :-þ
[I'm not that Good, obviously]
