Rollo's Philosophy [Air] (The Rollo Series)

192 pp. "The main design in view, in the discussions which are offered to the juvenile world, under the title of The Rollo Philosophy, relates rather to their effect upon the little reader's habits of thinking, reasoning, and observation, than to the additions they may make to his stock of knowledge." CONTENTS: Lost in the snow; Flying; Valve Making; Experiments; Pressure; Ballooning; Philosophical discussion; Tasks; Burning; Gravitation; Air in motion; Air at rest.