Included are two of the eight units of the Intermediate Science Curriculum Study materials designed for grade nine students. These are "investigating variation" and "winds and weather." Introductory notes to the student explain how the book is to be used. Each chapter starts with a short statement of a general problem, then concepts are developed chiefly through laboratory activities. The workbook format gives instructions for activities interspersed with questions and spaces for answers. Open-ended problems are included. The instructions and some of the questions and explanatory material are illustrated, and data tables are provided for students to fill out. Students are directed to excursions from appropriate points in the chapters; some of the excursions are remedial, others allow students to explore certain ideas further. (EB)