# On This Day

• ### 4-16-1673

Leibniz wrote to Oldenburg about series: "I conjecture that Mr. Collins himself does not speak of these summations of infinite series because he brings forward the example of the series 1/2, 1/3, 1/4, 1/5, 1/6, ... which if it is continued to infinity cannot be summed because the sum is not finite, like the sum of the triangular numbers, but infinite. But now I am cramped by the space of my paper."

Gottfried Leibniz
Harmonic Series
• ### 4-16-1705

Isaac Newton knighted by Queen Anne at Trinity College.