Wolfram Research
Wolfram Math World: Laplace Limit
This page gives a brief explanation of the Laplace limit, the value of "e" "for which Laplace's formula for solving Kepler's equation begins diverging."
Wolfram Research
Wolfram Math World: Exponential Function
This site contains graphs of the exponential function, identities relevant to the function, and the Maclaurin series for this function.