The Draughtsman's Handbook of Plan and Map Drawing / Including instructions for the preparation of engineering, architectural, and mechanical drawings.

by George G. André

—Having laid off on the circumference of the arc, the distances apart of the radii, as A, B, C, &c. ([Fig. 13]), from each of these points, with radius greater than a division, describe arcs cutting each other as at a, b, c, &c., join A a, B b, C c, &c., and the lines so drawn will be radii of the circle as required.

Fig. 14.

To construct an Oval, the width being given.

—Draw the line A B ([Fig. 14]) equal to the width, and bisect A B by C D (see [Fig. 1]). From the point of intersection E, with radius E A or E B, describe the circle A C B F, and from A and B through F, draw the lines A G and B H. From A, with radius A B, describe the arc B G, and from B, with the same radius, describe the arc A H; also from F, with radius F G or F H, describe the arc G D H, which will complete the required oval.

Fig. 15.

To construct a Square on a given line.

—Let A B ([Fig. 15]) be the given line. At A erect a perpendicular (see [Fig. 2]), and from A, with radius A B, describe an arc cutting the perpendicular in C; also from B and C, with the same radius, describe arcs cutting each other in D; join C D and B D, which will complete the required square.

Fig. 16.