Possible Clues:

• Friend and colleague of Bernoulli
• Pioneer in number theory
• Mathematician sounds useful with troubled waters
• Eighteen-hole game
• Mathematician seen on a Swiss 10-franc note
• Mathematician whose work led to the invention of 4-Down
• Mathematician whose work pioneered concepts represented by the symbol at the center of this puzzle
• Pioneering mathematician
• Swiss author of "Elements of Algebra"
• Mathematician whom Laplace called “the master of us all”