In the realm of UFOlogy, this book was not only one of the first, but also one of the best reports ever written on the subject. I first read it in the early 1950's, and believe me, it is perhaps the one book that fueled my interest not only in UFO's but in all forms of Fortean Phenonema, both past and present for the last fifty-three years. No fadism in the pages of this excellent tome - just cold, hard, and well researched facts about a subject that is now more popular than when this book was first published in 1950.
Written in 1950, this book cannot be said to have been influenced by the massive hype and disinformation that has surrounded the subject ever since. The author demonstrates none of the hysteria that characterizes so much of this genre. In addition to being informative, the book is a great read, more like a novel than a work of non-fiction. However, one never gets the sense that Kehoe is embellishing for effect. This is solid reporting. One element of the story that the book does not cover (as it emerged later) is the wide range in sizes these objects manifest, and their extremely varied form factors. Some, evidently, can take on the appearance of biological organisms, even quite small ones. For instance, I have seen such UFOs in my apartment, usually in the kitchen, and they look exactly like houseflies. After many years of observation, I have noted that these UFOs, for some reason unknown to me, return to their home galaxy in the Winter months, only to return in the Spring. Nowhere have I found a credible explanation for this in the extensive literature on the subject of unidentified flying objects.