These hand-held calculators are specially designed to perform repetitive calculations connected with a specific activity or industrial process and have the advantage of being simpler than a conventional slide rule to operate and more convenient to use and less expensive than electronic calculators or computers. For these reasons they are still produced and are often used as promotional items in addition. In these slide charts,made of card,one relates to vibration problems and the other to those in photographic instrumentation | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Terry, Sheila |
Bildgröße: | 5145 px × 3430 px |
Modell-Rechte: | nicht erforderlich |
Restrictions: |
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