A must read for anyone who cares about the future of humanity. A detailed collection of quantifications. Answers to questions about engineering and farming that must have taken great effort to research. From calculations about how many hectares of land it takes to grow the food to feed a draft animal, to surprising insights into our most powerful prime movers to date. Reading this book has changed my approach to how I run my business and home for the future. And will reside on my shelf as a reference for years to come.