Maybe it isn't. The one customer review of this thing says that it is just a reprint of a not very good book published in 1930. The original covered only French gargoyles and was not well laid out, poorly researched, and badly written. I have sent for it and a few others with the word 'gargoyles' in the title. I may yet become an itinerant
photographe living in a gypsy van. I will know in a few days. It might even provide a place to start and plagiarize from using better modern technology. It might be that the main significance of this thing is that somebody at Dover Press recently thought that a book of photographs of gargoyles was worth publishing.