1. This is a simple rule and, as its name acknowledges, is very
much a beginner's slide rule.
2. The trig scales are on the back but have a window/hair line which extends for the full
height of the slide and so enables sin, log and tan values to be calculated at one end of
the rule only. The sin scale is used with the A scale and the tan scale with the D scale.
3. The rule also gives a series of settings for unit conversion. Whilst this technique can
be seen on other rules, as used on this rule there are number of interesting differences.
- The settings used appear to be Keuffel and Esser's own; certainly many of them are different to those on other rules. For example the conversion from yards to metre is given as 171/187 on this rule and 32/35 on the others. The K & E figure is more accurate 1:24000 compared to 1:8000 for the others but, given the accuracy of a slide rule, this difference is not really significant.
- They acknowledge the source of the equivalents and abbreviations: U.S. Bureau of Standards Circular No.47.
- A number of formulae are given using p but slide rule settings are not given for this. There is a however a gauge mark for p on the A and B scales; this clearly shows how the makers expected calculations using p would be performed.
4. Other rules with similar tables are: Lawrence 10B, Hemmi - 40RK and Faber Castell 360.
5. This rule in some respects resembles a Lawrence except that the faces of the K and E are painted white but those of the Lawrence are varnished.
