
 Logarithm  Wikipedia, the free encyclopedia 
  Logarithms to various bases: red is to base e, green is to base 10, and purple is to base 1.7. 
  One simply found the logarithms of both numbers (multiply and divide) or the first number (power or root, where one number is already an exponent) in a table of common logarithms, performed a simpler operation on those, and found the result on a table. 
  This he followed, in 1624, by his Arithmetica Logarithmica, containing the logarithms of all integers from 1 to 20,000 and from 90,000 to 100,000 to fourteen places of decimals, together with a learned introduction, in which the theory and use of logarithms are fully developed. 
 en.wikipedia.org /wiki/Logarithm (2054 words) 
