You can make one form of engineer's level (Fig. 61) as follows: Take a full length of No. 6 tubing, bend it up 4 inches at each end, smooth the ends, attach it to a small board, rest the board on a one-legged table, and you have a serviceable level (Fig. 62).

Fill the tube with water, shove the pointed end of the leg into the ground and sight along the outside of the upright tubes at the level of the water surfaces. The line along which you sight is exactly horizontal, because the water surfaces are at exactly the same level.

A Simple Engineer's Level (From Aidrous' Physics. Courtesy of The Macmillan Company)

Fig. 62. One-legged table and level

Repeat with other friends.