Announcing a new addition to the Here Is Your Hobby series which includes such titles as Fishing, Stamp Collecting, Archery and Ceramics. The emphasis here is not on the science experiment itself, but on the construction of equipment necessary to demonstrate some project. Numerous ideas can be divided into five categories: Collecting Things, Observation Aids, Experimenting Equipment, Measuring and Weighing and Mounting and Displaying. Young scientists in dire need of a box-trap, an optical bench, an air oven or a psychrometer can combine their ingenuity with these photographed and diagramed instructions.