Columbovo egg. Ignatiev I.

The book of St. Petersburg Professor Ivan Ignatiev is devoted to the simplest physical phenomena, which clearly demonstrates the properties of liquids and the action of the main physical forces, such as inertia, gravity, and elasticity. Guided by this book, you can create visual aids for the home office of physics with your own hands, and in addition, surprise your friends and acquaintances with incredible at first glance focus based on physical laws.