This books appears to have been neglected elsewhere. It is noteworthy in containing Tesla's lectures from the early 1890s, that excited so many people at the time. It was published in 1894 and is on archive.org:
I went looking for it while reading William Lyne's books (yeah, I tend to read several books at the same time): Pentagon Aliens and Occult Ether Physics - Tesla's Hidden Space Propulsion System and the Conspiracy to Conceal It, the latter of which is, according to the Gestalt Reality site, recommended by Eric. Lyne quotes extensively from the 1894 book.
Why follow up such a trail? Well, Lyne claims, among other things, that Tesla invented an electric propulsion system for aircraft (in the 1890s!) and that that system was subsequently developed into that used by flying saucers / UFOs (which are a government program). I'm interested in examining the evidence in support of his claims.
My curiosity is also piqued by the fact that Eric has not, as far as I'm aware, researched Tesla's electric propulsion technology, if it exists. Yet he recommends Lyne's book.