The Mathlog method used to return the natural logarithm base e of a number. MathE returns Eulers number. Because log10 is a static method of Math you always use it as Mathlog10 rather than as a method of a Math object you created Math is not a constructor.
Javascript log example Example 2.
Description In JavaScript log2 is a function that is used to return the base-2 logarithm of a number. The JavaScript Mathlog function returns the natural logarithm of a number. This function is the equivalent of Mathlog x Mathlog 10. Because the log2 function is a static function of the Math object it must be invoked through the placeholder object called Math.