On one Side of this Scale is placed seven several Scales of Lines, five of which are divided into as many equal Parts as the Length of the Plotting-Scale will permit. The other two are likewise equal Parts, but have two Lines of Chords of different Lengths joined to them. The first of the equal Divisions, on the first Scale of Lines, is subdivided into 10 equal Parts, at the Beginning of which is set the Number 10; signifying, that ten of those Subdivisions make an Inch: that is, in this Case, every of the Divisions on the first Scale, is exactly an Inch; at the End of the first of which, is set 0; at the End of the second 1; at the End of the third 2; and so on to the End of the Scale. The first of the equal Divisions, on the second Scale of Lines, which are lesser than the Divisions on the first Scale, is likewise subdivided into 10 equal Parts, and hath the Number 16 set at the Beginning of it, signifying, that 16 of those Subdivisions make an Inch, or one of the Divisions \(\frac{10}{16}\) of an Inch; at the End of the first of which is placed 0; at the End of the second 1; at the End of the third 2: and so on to the End of the Scale. The first of the equal Divisions on the third Scale of Lines, which are lesser than the Divisions of the precedent Scale’s, is also subdivided into 10 equal Parts; at the Beginning of which is set the Number 20; signifying, that 20 of those Subdivisions go to make an Inch, or that one of the Divisions is \(\frac{10}{20}\) or \(\frac{1}{2}\) of an Inch, which Divisions are marked, 0, 1, 2, 3, and so on to the End of the Scale, Understand the same for the other four Scales, at the Beginnings of which are writ, 24, 32, 40, 48; only the Divisions of the two last Scales of Lines are not continued to the End of the Scale, because of two Lines of Chords of different Lengths, the Beginnings of which are marked by the Letters C, C, signifying Chords. The Construction of which see in the next Chapter.

*Note*, Each of the aforesaid Scales of Lines are aptly distinguished from one another, by being called Scales of 10, 16, 20, 24, 32, or 48, in an Inch; as the first Scale, is a Scale of 10 in an Inch; the second, 16 in an Inch; the third, 20 in an Inch; the fourth, 24; and so on.