The document appears to be a diagram of a circular slide rule used for mathematical calculations. The slide rule contains two concentric circular scales for performing multiplications and divisions. It also includes trigonometric scales for calculating sine, cosine, and tangent functions. Additional inner scales are provided for exponentiation and logarithmic calculations.

1. 3
0
1.3
e
20000
1.40
1.4
10000
e
2.7 1.11
1.35
0
5
1.5
0
1
1.5
.16
1.6
1.
14
1.8
5
1.1
1.20
1.2
5
9
6
7
1.3
5
1.7
1.2
4
.17 .18 .19
50
.15
40
1.4
30
500
2.5
20
2.
SIDE 2: INNER SCALES, FOR EXPONENTIATION
00
20
1.12
1.1
3
15
.14
4
1.2
1.3
π
e
1.1
.12
2.3
1.1
SIDE 2: OUTER SCALE
1
3
0.3
3
1
.11
2.2
9
e
e
3
π
π
0.4
4
4
7
SIDE 1: INNER MULTIPLICATION SCALE and TRIG SCALE
1.3
.13
00
0
9
1.1
π/2
1.2
10
10
8
1.0
1
1.1
8
1.6
0.9
π/4
SIDE 1: OUTER MULTIPLICATION SCALE
9
1.3
500
200
0.8
0.5
2.0
1.5
5
6
5
1.9
1.8
1.7
0.7
0.6
8
6
1.9
1.6
1.6
5
Copyright (C) 1997 by Charles C. Kankelborg
1.7
1.7
1.8
1.8
1.9
1.9
CIRCULAR SLIDE RULE
6
5
7
7
0.2
2
1.4
1.5
2
10
8
1.4
1.5
2