Ten real slide rules and related calculating instruments: K&E, Aristo, Faber-Castell, Pickett, Nestler, cylindrical Fuller and Otis King models, plus Concise, KL-1, and a slide-rule pocket watch. Photograph credits: 1. File:Slide rule K&E 4181-3 front.agr.jpg; ArnoldReinhold; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Slide_rule_K&E_4181-3_front.agr.jpg; 2. File:1959 engineering slide rule Aristo Nr 967U by German company Dennert and Pape Aristo Werke.jpg; R. Henrik Nilsson; CC BY 4.0; https://creativecommons.org/licenses/by/4.0; https://commons.wikimedia.org/wiki/File:1959_engineering_slide_rule_Aristo_Nr_967U_by_German_company_Dennert_and_Pape_Aristo_Werke.jpg; 3. File:Faber Castell 2 82 slide rule front.jpg; Slashme; CC0; http://creativecommons.org/publicdomain/zero/1.0/deed.en; https://commons.wikimedia.org/wiki/File:Faber_Castell_2_82_slide_rule_front.jpg; 4. File:Pickett N4ES slide rule front.agr.jpg; ArnoldReinhold; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Pickett_N4ES_slide_rule_front.agr.jpg; 5. File:1947 or earlier Albert Nestler slide rule no 11 made in Lahr Germany.jpg; R. Henrik Nilsson; CC BY 4.0; https://creativecommons.org/licenses/by/4.0; https://commons.wikimedia.org/wiki/File:1947_or_earlier_Albert_Nestler_slide_rule_no_11_made_in_Lahr_Germany.jpg; 6. File:Fuller's calculator.jpg; Thincat; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Fuller's_calculator.jpg; 7. File:Otis King cylindrical slide rules, view 1 - Ridai Museum of Modern Science, Tokyo - DSC07491.JPG; Daderot; CC0; http://creativecommons.org/publicdomain/zero/1.0/deed.en; https://commons.wikimedia.org/wiki/File:Otis_King_cylindrical_slide_rules,_view_1_-_Ridai_Museum_of_Modern_Science,_Tokyo_-_DSC07491.JPG; 8. File:Concise Circular Slide Rule.jpg; Wtshymanski; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Concise_Circular_Slide_Rule.jpg; 9. File:Russian circular slide rule (model KL-1).jpg; Wojciech Biegun; CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0; https://commons.wikimedia.org/wiki/File:Russian_circular_slide_rule_(model_KL-1).jpg; 10. File:Slide rule designed by William Froude, manufactured by Troughton & Simms, 1877 - Science Museum, London - DSC05598.jpg; Daderot; CC0; http://creativecommons.org/publicdomain/zero/1.0/deed.en; https://commons.wikimedia.org/wiki/File:Slide_rule_designed_by_William_Froude,_manufactured_by_Troughton_&_Simms,_1877_-_Science_Museum,_London_-_DSC05598.jpg;