From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Observations of sparks from various magnetos using two different types of revolving spark gap apparatus.
| Identifier | ExFiles\Box 63\4\ scan0001 | |
| Date | 26th May 1918 | |
| X 3109 EFC8/T26.5.187 OBSERVATIONS OF VARIOUS TYPES OF SPARKS AND SPARKS FROM VARIOUS MAGNETOS ON REVOLVING SPARK GAP APPARATUS Two types of revolving gap were tried:- (A) This consisted of an earthed revolving circular disc (about 11" dia) with sharpened edges ( like a bacon slicer) and a stationary insulated high tension point whose distance from the moving periphery of the disc could be easily varied. Speed of periphery 122 ft/sec. Fig A (B) This consisted of an earthed stationary square disc with a large circular hole, (about 8" diameter); the periphery of which hole had sharpened edges facing inwards, together with a revolving high tension metallic point, carried by a revolving circular disc of insulating material. The metallic point formed a projection from a flat metal ring concentric with, and attached to, the insulating disc. An insulated brush pressing upon this ring fed the high tension current to the point. Contd. | ||