# On This Day

• ### 7-31-1669

Newton became known. Lucasian professor Isaac Barrow sent John Collins a manuscript of Newton's De analysi and thereby Newton's anonymity began to dissolve. De analysi was a summary of Newton's work on the calculus and was written after Newton saw Nicholas Mercator's Logarithmotechnia (1668), which contained a series for log(1 + x), in order that Newton would not lose credit for his work on infinite series. Collins immediately recognized Newton's genius. Although this manuscript was not published until 1704, it led to Newton's appointment as Lucasian professor on 29 October 1669.

Isaac Newton
Isaac Barrow
John Collins
Nicolaus Mercator
• ### 7-31-1704

Gabriel Cramer born in Geneva, Switzerland. Best known for Cramer's Rule for solving systems of equations, he worked primarily in analysis.