2. In addition to he scales shown it has measuring scales on both edges. These are graduated identically, in inches and quarters, on both edges. The rule itself is 24" long.
3. On the front the rule has 4 scales, labelled as A, B, C and D; with A, B, and C being 2 cycle logarithm, B and C being identical and A being a single cycle logarithm. This rule is used in a similar way to the Coggeshall rule.
4. On the back the rule has scales labelled E, B, C and A. The A, B, and C scales are identical to those on front (except for the position). The E scale is labelled "inverted line". The values are equal to those on the A scale times 0.693. I've no idea of the significance of this figure.
4. The rule has gauge marks for calculations involving the diameter and the girt (i.e. girth = circumference.). On of the gauge marks is 13.54. By setting the length of cylinder in feet on C against the gauge mark on D, the volume in cubic feet can be read against the diameter in inches on D.
Front view
Detail front
Detail back
Gauge points for girt (circumference) and diameter
