Bottle of Magic traces the development of the electron tube from the pioneering efforts of such scientists as Lee de Forest, Thomas Edison, and John...
Six-year-old Betty visits a poultry farm, where she helps feed the chickens, sees them at various stages of development, watches a boy clean the eggs...
DEMONSTRATES LIGHT AS A FORM OF RADIANT ENERGY. EXPLAINS THE PRINCIPLES OF REFLECTION & REFRACTION & SHOWS HOW THESE PRINCIPLES APPLY TO THE SCIENCE...
