The Office of Naval Research investigation of Townsend Brown’s tethered discs, carried out in June 1952 by Willoughby Cady during the period when Brown was seeking backing for Project Winterhaven.
What it found
Cady logged the devices at roughly 1.5 percent efficiency and about eight grams of thrust, and attributed the result to ion wind rather than to any coupling between charge and gravitation.
Why the document matters more than its size
It is the earliest instrumented negative result in the whole electrogravitics literature, it was produced by the service Brown was asking for money, and it is present in Secrets of Antigravity Propulsion’s own material. Paul LaViolette reports it and does not set it against the classification reading of the 1959 silence, which is the book’s central inference. The competing reading, that an enthusiasm collapsed once careful measurement attributed the thrust to ion wind, has this report at its head and the author’s own chapter twelve conclusion at its foot, and a reader deciding what the book establishes will spend most of their time between those two points.
Connections
Townsend Brown · Project Winterhaven · Electrogravitics · Biefeld-Brown Effect · Paul LaViolette · Secrets of Antigravity Propulsion · Lifter · Vic Bertrandias · Tom Turman