plumb line

"It's the lead weight from a plumb line."

Drop a plumb line from the top of the head down through the spine into the heels in first position, divide the body down this center, right from left.

“When I took down the remaining wallpaper in preparation for new wallpaper, I came across all her notes, measurements and marks for plumb lines. It brought back so many memories.”

The referee goes to or near the spot where the ball was punted and watches its flight, drawing an imaginary plumb line between that point and where the ball intersects the sideline.

Then, using a level in the vertical position, draw a straight vertical line on the wall in pencil; this is called a “plumb line.”