How do I make a model helicopter or roller skate, paper boat or bird feeder, water ski or steerable sled? A lot of such questions constantly arise among young craftsmen. The Encyclopedia, composed of descriptions of various designs, can answer them. She will tell you how to equip an apartment, a summer cottage or garden plot, a playground or a sports ground with convenient devices. It will help to make funny toys for kids and demonstration devices for chemical experiments, teach you how to make props for tricks, equipment for a puppet theater and circus, and many other crafts.