Laying is the skill of making equipment level. It usually involves moving equipment in small motions so that spirit levels are centralised in all planes. Movement is usually done by small worm gears or other fine setting devices for accurate small movements, together with other more coarse gears to allow large swings in motion for quick movement between different settings.
Equipment that requires laying before it is can be used accurately includes:
Other uses
Laying is also the name given to backing an event to lose, for example betting on a horse to lose.
"Laying Out" is a term given to a diving catch in sports.
Laying is also incorrectly used when the word 'lying' is meant, as when someone says a person is laying down when a person is lying down is what was intended.