This book was recently written about and recommended by Mats Abelli and Maurice Leakey as part of Tom P.'s request for info on various projectors. (This book may have been previously discussed by others here as well, not sure though). This book covers many film projectors in 9.5, 16mm, Super 8 and 8mm.
While this is a very expensive book, it is a true goldmine of information about both the popular brands as well as the little-known projector brands. It is well worth it to keep an eye out for a copy of this book at a price you may find reasonable.
It is a dual-language book written in both German and English. In fact, it has dual book covers--one in German and one in English (as shown in the next two pics). The pages of text alternate between German and English. This makes it a little confusing to follow along at first, as you still need to examine the pictures on ALL of the pages regardless of the language.
In-depth articles about the history and unique features of various brands/models are provided as well. These two Fumeo pages show how one page is German and the next is English....
And there is some fascinating history about the use of Super 8 projectors on airline flights with pics of some of the equipment that was used:
Then, if you flip the book around you get the catalog portion, covering 2,800 projectors. Numerous pictures of various models are shown as well as charts with more detailed feature info.
Hope these pictures showcase what a great book this is. I believe the author, Jurgen Lossau, has a similar book covering Movie Cameras, and a paperback book called "Cut" which covers various film splicers.