Historical Telegraph Key Diagram - Labeled Mechanical Morse Key Illustration #294205 (License: Personal Use)

This black-and-white technical drawing depicts a traditional manual telegraph key, featuring a lever (s), contact spring (e), baseplate (m), and adjustable tension screws (α, n). The large circular dial (α) likely controls spacing or damping, while the curved arm (L) provides ergonomic operation. Such keys were central to landline telegraphy from the 1840s through the early 20th century.

Used on educational, historical, or museum web pages explaining the evolution of telecommunications; serves users researching vintage radio/telegraph equipment, STEM history lessons, or restoration guides for antique devices.