I bought this because I had seen it reviewed as being a classic of scientific writing, and the subject interests me. I confess that I only got through the first two chapters. After the introductory chapter, the second chapter (on physical constraints on growth), had many interesting things to say but said them in a laboured way and it was hard to see what relevance some of the illustrations had to the text - this could have been the result of the book being edited down from over 700 pages to only 360. I felt that the occasional equation was introduced more for effect than from necessity.
My appetite to finish the book disappeared, nor did I wish to read the full version to see if it flows better. However, it has stimulated me to look for a modern book on the same subject. Maybe it will do the same for you!