Took a while to get through this, but being a collection of technical works on very old motors from the 19th century, that’s not surprising. It was fun to see the same DC dynamo’s that started Tesla on his quest to create the AC induction dynamo/motor. The only thing that really dragged the rating down for this book was not the writing in and of itself but rather the layout. Diagrams were placed in the chapters that made referencing and understanding the basic principles being describe a real pain and very distracting. Having to move several pages ahead or back while following a procedure that is heavily referencing diagrams scattered about the chapter leads to some very confusing reading.