Mechanical Drawing Self-Taught / Comprising instructions in the selection and preparation of drawing instruments, elementary instruction in practical mechanical drawing; together with examples in simple geometry and elementary mechanism, including screw threads, gear wheels, mechanical motions, engines and boilers

by Joshua Rose

Fig. 179.

Fig. 180.

Draw the line O P, Figure 181, and at a right angle to it the line O B; divide these two lines into parts of one inch, as shown in the cut, which is divided into inches and quarter inches, and from these points of division draw lines crossing each other as shown.

Fig. 181.