Aristo Nr. 0903 Scholar, 10" Simplex
Aristo is a German company; they made very nice slide rules. I like this rule because it is so colorful. All plastic, it probably dates to the 1960's.
Aristo slide rules were imported into the United States by Charvoz, who relabeled them "Aristo-Charvoz". I also have an Aristo-Charvoz No.870, which is equally nice.
C-Thru No. 88 and No. 27 Mannheim Slide Rules
These two slide rules are bottom-of-the-line slide rules, being made from folded plastic. One is 10" and the other 6". They're interesting because the inch and centimeter rulers are on the slide, which has to be removed from the stator for the rulers to be used. I wonder how many lost slides that produced?
Unknown non-Logarithmic slide rule, 12" Simplex
This isn't really a slide rule, as the scales are linear, not logarithmic - which is to say, they're for adding and subtracting, not multiplying and dividing. But it looks like a slide rule, so that is what I call it (it beats "thingie"). I have no idea what it is for.
© 2003 W. E. Johns