Scale (Lat. scala, a ladder), a graduated line or slip of wood, ivory, metal, or paper, divided into parts equal or unequal, and used for transferring these parts by dividers in plotting. The most simple scale is that of equal parts, and this may serve not merely for giving proportional linear spaces, but also for laying down angles with greater accuracy, the table of chords being referred to to give the proportional length of the chord of any angle to the radius of the circle. The common six-inch ivory scale contains several scales, each of which presents a different division of the inch, as into quarters, and one of these into tenths, and each tenth by what is known as the diagonal scale into 10 parts; other divisions are into 3, 3 1/2, 4, 4 1/2, 5, and 6 equal parts, one of each of these being divided into tenths, and one of each of the principal divisions into twelfths. These scales are also sometimes furnished with trigonometrical lines, as scales of chords, rhumbs, sines, secants, and tangents. (See Gunter, and Sector.) Scales of equal parts have of late been produced in a very convenient and cheap form upon paper, the divisions being of 12 inches, and a 13th inch which is divided into 20, 40, 50, and 60 equal parts.
Other scales give different divisions.
See Weighing Machines.