I did a search and found nothing referencing this book. I hope I'm not re-hashing old info.
I got this book on the recommendation of another baker and a second recommendation from a caterer friend, both know that I like to work on old or antique recipes and bring them into the present.
Sometimes they work and sometimes they are a disaster.
This book is different in that while it does have recipes, it also has "formulas" that are basic explanations of why things behave the way they do.
As he gives the formulas in "parts," i.e., the standard ratios of flour, liquid, fat, etc., the development of a recipe should work with any measurement system and might make it easier to convert recipes from one system to another.
In any event, I am very pleased with the book and recommend it highly.
Soon after I got the book I made the Canadian Bacon, following his instructions to the letter. It was simply amazing.
This site has a pretty good preview of the book with some of the essential points.
http://books.google.com/books?id=zGaRpi4YdIQC&dq=Ratio+by+Michael+Ruhlman&printsec=frontcover&source=bl&ots=HNKNzAFGR3&sig=7ZyPjdT_aUpSfzOIG6GeIQwXtQA&hl=en&ei=WeEeS8y_H43UsQOy-PTsCQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CCYQ6AEwBQ#v=onepage&q=&f=false