Recording discs for Emidicta Model 2403 recorder for GPO use Recording discs for Emidicta Model 2403 recorder for GPO use
End disc from destination indicator, Mersey Rly, Brass disc with ivorine tablets from train destination indicators fitted to 1903 Mersey Rly railcars End disc from destination indicator
Small silver disc (1" diam.) engraved with an early design of Sir George Cayley for a glider or heavier than air flying device (dated 1799) Small silver disc engraved with an early design of Sir George Cayley 1799
Rayleigh disk: includes Rayleigh disk, mounted in glass box Galvo lantern and enclosed scale; Oscillator unit. Rayleigh disk: includes Rayleigh disk