On Euler and Chebyshev, at the foundation of Russian mathematics

On the occasion of Chebyshev's two-hundredth anniversary, I review part of his work, showing that in several respects he was the heir of Euler. In doing this, I consider the works of Euler and Chebyshev on three topics in applied science: industrial machines, ballistics and geography, and then on three topics in pure mathematics: integration, continued fractions and number theory, showing that in each filed the two mathematicians were interested in the same kind of questions.