A Convenient, Home-Manufactured Plumb
is made by dividing a straight piece of board with a black line, exactly in the centre, extending from end to end. This piece is notched at one end in the same manner as the previous one, and a string and weight attached, as shown by Fig. 65. By placing the edge of this against a wall it can be determined whether it is in or out of plumb.
Fig. 65.
The boy who can manufacture these two tools can, with the aid of other boys, build himself