I bought this book thinking it was devoted to the gravity lens effect. It has one chapter about this topic. That was disappointing. However it’s the best non-mathematical explanation of the effect and its uses that I have seen.
The first half of the book is an introduction to the great questions of astronomy. It is well-written and timeless because it is history.
The rest of the book is a survey of the state-of-the-art of astronomy as of 1988. Which is merely confusing because some things have been resolved. Dark matter, for example, was a new idea then, but seems to be accepted now, even though I don’t see much progress in understanding or capturing any of it.
The field of astronomy seems continue to evolve. I would recommend buying a more current book.