This book is a collection of texts in Russian on mathematics, physics, astronomy, and chemistry. The texts have been abridged and slightly adapted. They have been so selected as to include the most widely used vocabulary within the limits of the material dealt with in this book. The book is intended for the student of the Russian language and aims to get him acquainted with the vocabulary and style of Russian popular science literature, and to a certain extent to prepare him to read original Russian scientific books.