Notes 1. This rule has a rather unusual and, to my eye, attractive
appearance; it is plain metal. The surface is brushed aluminium and the lettering is
engraved so the whole rule is smooth to the touch. The lettering is not perhaps as clear
as on Pickett rules, which also used Aluminium but were coated either in white or yellow,
but still presents no problems.
2. The rule has an interesting complement of scales; there is an A scale but no B scale
and the log-log scales are on the slide rather than the stock. The latter feature is not
unique but is quite rare.
3. The cursor is multi-line with a Öp/4 line for with the A
scale for circle calculations. This is shown on the cursor front view below where the
principal line of the cursor is set at the diameter of 2 and the area 3.14 (i.e.p ) is read on the A scale. The use of the hair line to the right,
the same distance from the principal line as the other, is less obvious.
4. The cursor has another unusual feature in that it is narrower on the back than one the
front. This enables the principal line of the cursor to reach the full extent of the
scales on the front.
5. The rule follows the continental European practice of using the comma (,) to mark the
decimal. This can be seen most clearly on the L scale but is also noticeable on the
log-log scales. Whilst this is normal practice with written or printed numbers I have not
seen it on other slide rules.
|
Scales |
A, DF [CF, CI, C] D, L
T1, T2 [LL1, LL2, LL3]
D, S |