Phase 1
Inexpensive
-----------------
Readily available.
Approximate cost
Less than $30.		Phase 2
Medium Priced
-----------------------
Often more advanced.
Approximate cost
$30 to $100.		Phase 3
Higher Priced
---------------------
Scarce.
Approximate cost
$100 to $250		Phase 4
Highest priced
--------------------
Rare collector's items.
Approximate cost
More than $250

Dietzgen 1765P


Aristo 0869 StudioLog


Aristo 0972 Hyperlog


Charpentier Calculimetre


Dietzgen 1771 RediRule


Aristo 0969 StudioLog


Hemmi 257L Chemical


Dempster RotaRule


Dietzgen 1776 RediRule


Aristo 0971 Hyperbolog


Hemmi 260 Advanced Engineer


Faber-Castell 2/84 Mathema


Keuffel & Esser 4058


Dietzgen N1725


Hemmi 266


Faber-Castell TR-1


Keuffel & Esser 4053-3


Dietzgen G-1734


Keuffel & Esser 68 1130 Deci-Lon


Fuller


Keuffel & Esser 4081-3


Dietzgen 1741


Post 1451 Versatrig


Keuffel & Esser 68 1400 Analon


K&E 4181


Faber-Castell 2/83N


Post 1490 Frequency Response


Keuffel & Esser 4160 Chemical


Pickett N500ES Log Log


Faber-Castell 8/10


Post 1491 Chemistry


Cox Slide Rule by K&E


Pickett N600ES


Faber-Castell 1/87A


Pickett X3


Loga Daemen-Schmid


Pickett N1010ES Trig


Gilson Atlas Spiral


Pickett 110ES


Nestler Cylindrical


Pickett 120ES Microline


Hemmi 149A


Small Calculator


Billeter National No.16


Post 1441 Vest Pocket


Hemmi 255 D


Fowler Jubilee Magnum


Soho Slide Rule by Lenoir


Post 1444K


Hemmi 259


Halden Calculex


Thacher Slide Rule by K&E


Post 1447 Student


Keuffel & Esser 68 1100 Deci-Lon


Mannheim by Tavernier-Gravet


Lord's Calculator


Post 1460 Versalog


Nestler 0130


Hemmi 154 Electrical Engineer


Oughtred Circular Slide Rule


Gilson Binary


Nestler 0232 Rietz

 
Coggeshall Slide Rule


Gilson Midget


Nestler 0291

  

Aristo 0968 Studio


Nestler 0292

  

Aristo 0901 Junior


Otis King

  

Aristo 0903 Scholar


Post 1461 Versalog

  

Aristo 89 Rietz


Pickett N3pES

  

Faber-Castell 1/87 Rietz


Pickett N4ES

  

Faber-Castell 2/82


Thornton AA010

  

Faber-Castell 52/82


Fowler Jubilee Magnum

  

Nestler 11 ZM


Halden Calculex

  

Nestler 23R Rietz


Keuffel & Esser 4053-5

  

Nestler 0210

   

Hemmi 32

   

Hemmi 34RK

   

Hemmi 40

   

Hemmi 45K

   

Thornton P271

   

Unique Universal 2 & II

   

Unique 5/10

   

Graphoplex 612

   

Graphoplex 615

   

Graphoplex 620

   

Graphoplex 640 Rietz