Applying The Brakes By Switch.

A Simple Type of Electra-mechanical Servo Device Which Would Appear to Offer Many Possibilities. A N unusual type of electrically operated brake was exhibited at the Graham......

An Interesting Planetary Gearbox.

A New Design Notable for the Small Number of Gearwheels Employed. C ONSIDERABLE interest is being evinced just now in th& epicyclic or planetary type of gearbox, and we have......