My late father, Philip W. May, did the illustrations in this book app. 1946-47. Having worked in New York City for 20 years, more recently, and viewed how little the city puts into its infrastructure, I would imagine the book is probably still a very accurate view of the complicated web of wires, pipes, subways, etc. that weave below the streets. The book was contemporary when it came out, and more than likely still is to a great extent. It is also good history of how it all was done.