Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 16

A reliable method of dividing a board of any given width into any number of parts is illustrated by Fig. 11. Suppose a board 9 in. wide is to be cut into six equal parts; place the 1-ft. rule so that its ends touch the opposite edges of board, as shown in Fig. 11; draw a line right across, and upon this line mark off from the rule every 2 in., as 2, 4, 6, etc. Remove the rule, and draw lines parallel with the edge of the board, intersecting with the marks upon the oblique line, thus obtaining six parts, each really 1 1/2 in. wide. The principle of this is simple: 2 in. is the one-sixth part of 1 ft., and whatever be the slant of the rule across the board (and the narrower the board the greater will be the slant) each 2-in. mark must denote a one-sixth part of the width. Say a board anything less than 24 in. in length or width is to be divided into eight parts; then as 3 in. is one-eighth of 2 ft., use a 2-ft. rule in the same manner as before, and mark off at every 3 in.

Fig. 9.—Rule with Double Arch Joints.

Fig. 10.—Rule with Spirit Level.