are listed in order from top to bottom.
names are the labels actually on the slide rule or in Hemmi documentation.
If the scale name was not easily determinable, then the scale name is the
name in modern use.
“front” of duplex slide rules is arbitrarily defined to be the side
with the longer stator down. This is usually, but not always, the
side carrying the brand name and model number and the head of the body screws.
changed from time to time. In particular, on some rules all, some,
of the principal subdivision
between 1 and 2 on the C and D scales were explicitly numbered at different
times. It is beyond
our ability to note such variations.