[Tschebycheff] was the only man ever able to cope with the refractory character and erratic flow of prime numbers and to confine the stream of their progression with algebraic limits, building up, if I may so say, banks on either side which that stream, devious and irregular as are its windings, can never overflow.

In: E. Kramer, The Nature and Growth of Mathematics, Chapter 21 (p. 503)