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Medical and Scientific

• 41
• The Sphere Research Slide Rule Archives
• Slide rule model information, pictures, and history from all over the world.

• 42
• Antique Telescope Society
• International organization of colleagues interested in antique astronomical telescopes, books, binoculars and related materials.

• 43
• Scientific Instrument Society
• Bringing together people with a specialist interest in scientific instruments, ranging from precious antiques to electronic devices only recently out of production.