Well, both my general-information-Mithraism-book and my general-information-Zoroastrianism book are from the beginning of the previous century. Isn’t it odd that nothing really substantial has been written about these almost distinct but not less interesting religions in the last 100 years? And where “The Mysteries Of Mithra” is at least a ‘real’ book, this one looks more like a paper from school! It’s size is almost A4 and the cover is only sealed a bit. The pages are only printed for a quarter, so the book could easily have been much smaller. I do have another cover than the one you see here by the way. Mine is green and the symbol is a burning heart with an arrow through.
To the content then. Kapadia has written one long story and there is an ‘index’ in the beginning with the subjects per page, even though there are no chapters. His writings are quite interesting, nothing to say about that. You will really read about what Zarathustra and his followers had to say, how their community worked, its rules and regulations, a bit about the religious practises, symbols, names of the gods and demons, etc. etc. There is a second part with translations from a wide variety of texts by different early orientalists. Not only the well-known Gathas and apparently even not only from the Avesta, so this makes these translations quite interesting in themselves.
What is more strange that this book looks really cheap (photocopied and cheaply bounded), but I paid 10 pounds + tax + shipping, which brought the price to some 20 euro/dollar and between ordering and delivery the price even rose to as much as 30 euro/dollar! This book is obviously let run out of print, while it seems to be the only descent text about the Zoroastrian religion today, even while it is very old.