This was a Herald-Tribune Honor Book, and should have been covered some time ago, but it is too good to be omitted because we are late. It is exciting to see this sort of information available for youngsters who from five years old up are fascinated in watching the big machines at work. Here -- in excellent pictures in full color with accompanying descriptive text (not written down but as simple as the substance makes possible) are building and wracking machines that every city child sees at work. From the steam shovel on the cover and the crane on the end papers, the book goes through as follows:- bulldozer, tamping-leveling finisher, bucket loader, three-axle tandem roller, power tools, rock crusher, moto-crane, motor grader, diesel engine, motor scraper, concrete mixer, and building and wrecking tools... An answer to parents' prayers. Don't miss it.