D Some Collection Statistics
Total number of slide rules: 397.
Range of rule ages: 45 to 216 years. Average rule age: 83.5 years.
Number of rules at least 75 years old: 221. Number of rules at least 100 years old: 95.
Number of rules at least 125 years old: 18. Number of rules at least 150 years old: 11.
Number of rules at least 175 years old: 10. Number of rules at least 200 years old: 5.


Countries of the Slide Rule Makers
| Country | No. Rules | Makers |
|---|---|---|
| AUS | 1 | W&G |
| CHN | 6 | Shanghai Sida Slide Rule Factory, Shanghai Slide Rule Factory, Shanghai United Instrument Factory |
| DEN | 2 | Rietz |
| EGER | 1 | Reiss |
| FRA | 5 | MARC, Tavernier-Gravet |
| GER | 46 | Aristo, Dennert & Pape, Dietzgen, Faber, Faber-Castell, HH, KHH, Kolesch, Nestler, Staedtler |
| JPN | 48 | Alco, Concise, Hemmi, Relay-Ricoh, noID |
| UK | 26 | Blundell Rules Limited, Boots Ringplan, Davies, Dring and Fage, E.S.A. London, Fearns Calculators, Fowler, Gill, Halden, Jacob and Halse, Otis King, Stanley London, Thornton, Unique, noID |
| USA | 259 | Acu-Rule, American Blueprint, Baetzmann, Belcher Bros., Boykin, Bruning, C-Thru, Charvoz-Roos, Dietzgen, Engineering Instruments, Felsenthal, Festus, General Luminescent Corp, Gilson, Goodyear, Graphic Calculator, Gurley, Hansch, J.B. Carroll, K&E, Kahl Scientific, Kutz, Lawrence, Mims, Novotni, Okonite, P.A.S. Co., Palmer, Parisian Novelty, Pickett, Richardson, Sandish, Scofield, Sears, Sillcocks-Miller, Simplified Flight Calculator Co., Stanley, Sterling, The American Art Works, USA Mil, noID |
| USSR | 3 | Factory10, MATSKU, USSR Military |
Primary Construction Materials
| Material | No. Rules | Makers |
|---|---|---|
| Al | 53 | Gilson, Pickett, Reiss |
| bb | 42 | Dietzgen, Hemmi, Relay-Ricoh |
| iv | 1 | Jacob and Halse |
| Mg | 11 | Acu-Rule, Pickett |
| pl | 91 | Acu-Rule, Aristo, Blundell Rules Limited, Boots Ringplan, Boykin, Bruning, C-Thru, Concise, Dietzgen, Faber-Castell, Fearns Calculators, Felsenthal, General Luminescent Corp, Graphic Calculator, Gurley, J.B. Carroll, K&E, Kahl Scientific, MARC, Mims, Novotni, Parisian Novelty, Pickett, Rietz, Shanghai Sida Slide Rule Factory, Shanghai Slide Rule Factory, Sillcocks-Miller, Simplified Flight Calculator Co., Staedtler, Sterling, The American Art Works, Thornton, USA Mil, USSR Military, noID |
| pp | 4 | Goodyear, Okonite, Palmer |
| ss | 12 | Alco, Fowler, Halden, MATSKU, Otis King, P.A.S. Co., Richardson |
| wd | 183 | Acu-Rule, American Blueprint, Baetzmann, Belcher Bros., Charvoz-Roos, Davies, Dennert & Pape, Dietzgen, Dring and Fage, E.S.A. London, Engineering Instruments, Faber, Faber-Castell, Factory10, Festus, Gill, HH, Hansch, Hemmi, K&E, KHH, Kolesch, Kutz, Lawrence, Nestler, Pickett, Richardson, Sandish, Scofield, Sears, Shanghai United Instrument Factory, Stanley, Stanley London, Tavernier-Gravet, Thornton, Unique, W&G, noID |
- Key: wd (wood), bb (bamboo), pl (plastic), ss (stainless/steel alloy), Al (Aluminum), Mg (Magnesium), iv (ivory), pp (paper)