Cecil’s old column on Berlitz and Moore’s The Philadelphia Experiment was based on a question that read in part:
Over the years there have been a number of Comments threads with people wondering about what the third “city project” was. As in this 2005 example, the usual course has been that I pedantically point out the mundane origin of the name for the Manhattan Engineering District and that’s about it.
Anyway, I happened to stumble across a copy of The Philadelphia Experiment in a secondhand bookshop this afternoon and the question came to mind. (For one of the bestselling classics of Seventies pseudoscience, the book is surprisingly rare on the London secondhand market. Copies of Berlitz’s The Bermuda Triangle are far, far more common.) I wasn’t inclined to buy, so the following is based on a skim.
The only relevant assertion appears to be made in the preface. Berlitz claims that in 1943 the US had three major secret projects underway. The atomic bomb, antigravity and invisibility. The latter two were then abandoned once the first looked like succeeding. The last of these was the “Philadelphia Experiment”, so the answer to the question of what was the third project, at least according to Berlitz, appears to be antigravity. However, as far as I could see, he never gives a name for this project. Neither does he particularly link the names of the other two.
My guess: Cecil’s questioner had misread Berlitz and Moore. There was never any notion of three specifically named “city projects” therein.