Issue 2021 No 10 | A Norma Flyer | Issue 2021 No 10 | Eureka Slide Rule | ||
Issue 2021 No 11 | Smiths Lathework Calculator | Issue 2021 No 12 | Board of Trade Hydrometer | ||
Issue 2021 No 14 | Nash Logoscope | Issue 2021 No 14 | French Engineer's Slide Rule | ||
Issue 2021 No 15 | Slide Rule Instructions | Issue 2021 No 17 | Soho Slide Rule | ||
Issue 2021 No 19 | Dialling Beam Compass | Issue 2021 No 20 | Chemical Predictor | ||
Issue 2021 No 21 | Thomson's Lunar Corrector | Issue 2021 No 21 | The Mighty Colossus | ||
Issue 2022 No 22 | Ernst Sokopf Address Book | Issue 2022 No 22 | The German Patents | ||
Issue 2022 No 22 | Slide Rule Muldi | Issue 2022 No 22 | Forestier Rule | ||
Issue 2022 No 22 | Thomson's Lunar Rule | Issue 2022 No 22 | Amsler Patent Planimeter | ||
Issue 2022 No 25 | System Klepek |