SLIDE RULES
BY  D. DAVIS
ARCHIVE SITE
     For April we have two more model types aded to the basic ID pages, the 158 and 156. Both of them are electronics types, which have been gaining in popularity of late. Neither is exactly common, but are worth noting, so info is up on them.
      Also, another page added to the SIC section, this time with a confusing ripple in the 1530 evolution. A couple more confirmed brands have been added to the list on the first R/R page too, making 25 known brands identified. This, to my knowledge, is the most complete brand list anywhere. There can be little doubt that Relay/Ricoh rules were indeed the most re-badged brands ever. Hemmi may have gotten the drafting company Post's contract, but R/R got Pickett, Dietzgen, and a slew of scientific supply houses and electronics sellers!
     A good deal of effort has recently been spent by us on our new locomotives area, which is linked below, but FEAR NOT!! Slide rules have not been abandoned! We've got lots more good stuff to show you. Just gotta figure out how to stuff 37 hours in a 24 hour day!! Interest in Relay/Ricoh type rules continues to grow, so we'll keep abreast of it with continued research and images for you to enjoy, and to use in helping identify types you see.
HOW TO USE THIS SITE
  This site is intended to be a ready-reference for type identification. The most frequently seen types for both Relay/Ricoh and Dietzgen ( the duplexes for Dietzgen anyway, which are more common and collectible ) are all listed below. For Dietzgen, type i.d. is easy, but not so for Relay/Ricoh.
    Most of the re-brandings of R/R types are listed along with THE RULE THEY WERE MODIFIED FROM ORIGINALLY. So, from our list below, you will be able to navigate through the various types, and on each page several rules will be listed in text form, along with any known modifications and re-brandings. Eventually, links will be installed from the rule types to any relevant image pages found elsewhere on this site.
    If you don't find what you need there in these first sections, try our two MANUAL PAGES, both of which include model type catalogs! In fact, some people start out here, then after id'ing the rule they have or are interested in, check other sections for any further information.
    Last, take a look through our image archives, for id tips, and to see some unusual rules. Some age estimating information is also given here, and highlights on construction changes over the years. There's LOTS OF INFORMATION in the image archive!
    HAVE A RULE, BRAND, OR TYPE WE HAVEN'T LISTED YET? Send us E-mail from the DAVIS BROS. MASTER INDEX PAGE, which can be found through links below. We'll put it up, and credit YOU!  We hope you enjoy collecting, and using our site!
RELAY/RICOH ARCHIVES 
...pages of model types, manuals and other info.
UPDATED!! 150, 151, 153, 154, B-1734, 158, 156, B-1
...also an introduction to US Relay/Ricoh rules.
157, B-1725, 1737, 551,( Darmstadt type), 107
SIX PAGES!
252 (152), 102S, 550, 450, Nikkei 510
Image archive
1957 Relay manual/catalog
...with pictures!
UPDATED!!
1959 Relay manual/catalog
...with pictures!
UPDATED!!
The slide rules of S.I.C.
...with pictures!
NIKKEI SLIDE RULES!!
TWO PAGES!
Brand notes
brief notes about US distributors
DIETZGEN ARCHIVES Currently listing all known duplex types, with and without log-log scales!
1731, 1732, 1733, N1733 (N1731), N1732, 1734
B-1734, G-1734, 1738M, 1736, 1737, 1735, N1725, B1725, 1741
IMAGE ARCHIVE
1739L, 1779, 1773, 1778, 1744, 1746
1749M, 1743, 1745, 1751, 1776, 1771, 1768P, 1767, 1757
DAVIS BROS. ORIGINAL SITE!
Follow this link to see our original mega-site! MORE SLIDE RULES, featuring magazine type articles, as well as links to all the other sections or our site. Typewriters, sewing machines, even railway locomotives! Also links to many other sites.
TOP SLIDE RULE LINKS WORLDWIDE
A page of links to the very best slide rule sites in the world! Buy, research, discuss, whatever!
NEW!! LOCOMOTIVES@DAVIS BROS.
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