*In placing this book before the public the author wishes it understood that it is not his intention to produce a scientific work on engineering. Such a book would be valuable only to engineers of large stationary engines. In a nice engine room nice theories and scientific calculations are practical. This book is intended for engineers of farm and traction engines, *rough and tumble engineers,* who have everything in their favor today, and tomorrow are in mud holes, who with the same engine do eight horse work one day and sixteen horse work the next day. Reader, the author has had all these experiences and you will have them, but don’t get discouraged. You can get through them to your entire satisfaction.*