Napier's only rival for priority of invention of logarithms was the Swiss instrument maker Jobst Bürgi (1552-1632). Bürgi conceived and constructed a table of logarithms independently of Napier, publishing his results in 1620, six years after Napier had announced his discovery to the world. Though both men had conceived the idea of logarithms long before publishing, it is generally believed that Napier had the idea first. Whereas Napier's approach was geometrical, Bürgi's was algebraic. Nowadays a logarithm is universally regarded as an exponent. Thus n =b^x, we say x is the logarithm of n to the base b. From this definition the laws of logarithms follow immediately from the laws of exponents. One of the paradoxes in the history of mathematics is the fact that logarithms were discovered before exponents were in use.