Rules. The two-foot, four-fold rule (Fig. 3) is the one generally used by carpenters. It is made of different grades, the more expensive makes being divided into 16ths, 8ths, 10 ths, and 12ths, and having the J", 1/4", 3/8", i", !", 1", 1 1/2", and 3" scales upon them. Although the cheaper rule is just as accurate, it is divided usually into 8ths and 16ths only. The form of rule shown in Fig. 4 is becoming quite popular, as it is longer. Since rules are easily lost or broken, many workmen have a good rule for scaling, and a cheaper one for general work.

Fig. 3. - Two-foot, Four-fold Rule.

Fig. 4. - Zigzag Rule.