DIETZGEN ARCHIVE
    Here's another very under-rated slide rule maker. A drafting equipment supplier, they offered slide rules for many years. The debate still rages about just exactly who made what when it comes to Dietzgen. To be sure, many slide rules re-branded as "Dietzgen" were made by other companies. That's not in question. It's when you get to their standard wood and celluloid log-log duplex rules and the similar non log-log types that I'm unsure. Some strongly suspect that K+E made them. Boy, I can't be too sure. But some other, smaller Dietzgen types sure do match up with some K+E types, in size and style if not exact scale layout. Maybe someday we'll have a definitive answer.
     Another confusing thing about Dietzgen rules is just exactly what is what, especially in the log-log types. Fear not! Here, from my examples, from rules seen on E-Bay, and from perusing the slide rule archives of websites all over, we present an archive of DIETZGEN slide rules, to help YOU, the collector, sort out the types. This kind of thing exists for K+E rules, now here's a basic type archive for Dietzgen!
     If you consider the rules by SCALE SET, much as I do for K+E 4081/9081/4181 rules, it becomes much simpler. Odd that most neatly match up with a particular era K+E scale layout, you say? Yep, but it is no smoking gun. I have presented them (the wood log-log types) in a linear fashion, which I presume to be the order of manufacture, though currently I can't prove it! It seems, after lots of research, to be the correct order. It may not be. Anyways, hope you find it useful! We'll start with the big log-log types. Then on to others...
1732
LL0,LL00,A[ B,T,ST,S ]D,DI,K
L,LL1,DF[ CF,CIF,CI,C ]D,LL3,LL2
20 SCALES, 5 LOG-LOG SCALES
Notes: Wood and celluloid.Corresponds to the second K+E 4081-3 scale set, which K+E used 1939-47. A manual for these has been seen with a copyright date of 1946, so perhaps it did in fact correspond. Early versions have  a frameless cursor, which was patented by Dietzgen in 1946. (Mine is ser. no. 516081, a 1732.) "Decimal" referred only to the 1732, as the 1731 was min/sec format for the trig scales.
1731
        LL01,K,A[ B,T,ST,S ]D,L,LL1
LL02,LL03,DF[ CF,CIF,CI,C ]D,LL3,LL2
20 SCALES, 6 LOG-LOG SCALES
Notes: Wood and celluloid Corresponds to the third K+E 4081 scale set, used 1947-54. As with the previous scale set, this set apparently was available in either min/sec format (1731), or in degrees and decimal degrees (1732). As 1731's aren't common, this currently can't be proven, though 1732's of both the first two scale sets are known to exist, as well as 1731's of the top set. This theory makes sense, and parallels K+E's model availability with their 4080/4081 series rules. A 1732 like this just sold on E-bay in late Sept. 2002, two more June 2003, one of which I got!
1733
      LL01,L,K,A[ B,T,ST,S ]D,DI,LL1
LL02,LL03,DF[ CF,CIF,CI,C ]D,LL3,LL2
21 SCALES, 6 LOG-LOG SCALES
Notes: Wood and celluloid. Corresponds to K+E's fourth 4081 scale set, used by K+E 1954-55, until they introduced the "SRT" scale. "Polymath" probably was used corresponding with the re-introduction of the "DI" scale, as the non log-log 1744, which was contemporary, used this new name as well. Manual copyright 1953. This model may have replaced the 1732, but this is unclear. Also unclear is if there was a corresponding 1731. Some say this model differed from the 1732 only in wood edges, vs. celluloid, but this seems unlikely.
MANIPHASE MULTIPLEX ( DECIMAL) TRIG LOG-LOG.
MANIPHASE MULTIPLEX (DECIMAL)  TRIG TYPE LOG-LOG
POLYMATH MULTIPLEX DECIMAL TRIG LOG-LOG
N1733
         LL01,K,A[ B,T,T,ST,S ]D,DI,LL1
LL02,LL03,DF[ CF,CIF,L,CI,C ]D,LL3,LL2
22 SCALES, 6 LOG-LOG SCALES
Notes: This rule introduced what would be the final DIETZGEN scale layout, used on all further top end rules with the exception of a couple supplied by FABER-CASTELL. This layout splits the "T" scale into two sections ( <45 and >45 ), and moves the "L" scale onto the slide. This scale layout is the first to break from K+E arrangements. However, the use of the "N" prefix is again a decidedly K+E like thing. This rule was a normal wood and celluloid model. Many other rules would use this same exact layout of scales. All rules listed below, in this section, had the SAME SCALE ARANGEMENT, differing in construction as noted. If the RELAY/RICOH 151 is the most re-badged slide rule ever, then this scale layout may be the most reproduced in different styles. And even RELAY/RICOH got into the act!   (Note: N1731 MAY use this arrangement as well. It is known to exist for sure.) Manual copyright 1956, for N1733, N1732, and 1738M.
POLYMATH MULTIPLEX DECIMAL TRIG LOG-LOG
N1732
This rule adds a nifty and exclusive feature, what they called "MICROMATIC ADJUSTMENT". I own one of these, and it really works. In the top stator, in the end, there is a screw which passes through a threaded sleeve attatched to the end brace. All one needs to do to align the stator/slide scales ( with the rule closed) is turn this screw!! It is finely threaded, so precise adjustment is easily possible. They thought this would be a revolution, but apparently it wasnt as these are still nowhere near as common as contemporary K+E 4081-3's. Otherwise same as N1733, and used the same '56 manual.
1734
This rule takes the N1733 body and adds TEFLON in the stator grooves in which the slide rides. Sold as "MICROGLIDE" these used  TEFLON as a way to insure smooth operation under varying climactic conditions. These might be the most common of the "N1733" type rules. The name "MICROGLIDE" would appear again, as you shall soon see. First manual mentioning the 1734 was copyright 1959.
On the next page, we continue with rules using the same scale arrangement.
1732
1731