Kent editions go back, probably, 100 years or more. It comes in two volumes which are "Power" and "Design/Production" with the 12th edition and "Design/Shop Practices" with the 11th edition. Both editions, I have. They are excellent references along with other references such as Mark's ME handbook and Perry chemical engineering handbook which I studied for my PE license. I like these book because they are relatively small(8-1/2 by 5-3/4 inches)