Appleton's cyclopædia of drawing, designed as a textbook for the mechanic, architect, engineer, and surveyor (1866)
Worthen, William Ezra, 1819-1897, [from old catalog] ed, Appleton, firm, publishers, New York. (1866. D. Appleton & co.) [from old catalog] · New York, D. Appleton and company · leaf 42
RAWING INSTRUMENTS. 21 and technicalities, the signification of the terms chords, tangents, sines, andsecants, has been defined. Tlie chord of G0° is equal to radius, or lialf Rim , ^1 , M i , /,|,, 5!, , el, 7I ,«! [Lait :.,J^^. fro ,JoJo,4:,J Cho -^io • ^9^A.Jo..A.JgJ^JoJf> SJTv J^… … Fig. &4. the diameter. Tlie line of chords is used to set ofi an angle, or to measurean angle already laid down. To set off an angle.—An angle of 35° for instance : open the compassesto the extent of 60° on the scale of chords, setting one point at A on theline A B, describe with the other…
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