Device for measuring lateral spreading of electrons

1907-1908

Brass release device for bell jar

1800-1899

High frequency (violet ray) device

1920-1955

Electrical device for solving algebraic equations

Electrostatic indicating device consisting of two glass arms freely pivoted on a lightweight stand

1780-1798

A device for placing rings on the feet of racing pigeons

Lightning conductor earth: Cast iron self-watering device with grid

1918