Footstick

Every time, the bricklayers have to use their footstick to check whether the right height has been reached.

Source: wiktionary

The wee man crossed the footstick to where Johnny was and took him back over to his side.

Source: wiktionary

The footsticks may be a trifle shorter than the width of two pages and the gutter; for as there should always be a line of quadrats, or a reglet cut to measure, at the foot of each page, the footstick may be a pica shorter without danger, on this account, of any thing falling out, when the form is lifted and it thus prevents the side and foot sticks from binding when locked up.

Source: wiktionary

Neither the sidestick nor the footstick should project beyond the other, as it will prevent the quoins from passing, and in unlocking will give a great deal of trouble.

Source: wiktionary