What is one of two or more persons or gangs who work by spells. [R.] Their toil is so extreme that they can not endure it above four hours in a day, but are succeeded by spells. Garew called?

spell — One of two or more persons or gangs who work by spells. [R.] Their toil is so extreme that they can not endure it above four hours in a day, but are succeeded by spells. Garew. (Webster's 1913.)