What used to be be called "Euler's Constant" (http://en.wikipedia.org/wiki/Eulers_constant) is now frequently called the "Euler-Mascheroni Constant".
I have tried to find out what contribution Mascheroni made that merited his name being added to Euler's. All I have been able to turn up is that Mascheroni calculated $\gamma$ to a few more decimal places than Euler but the calculation had errors.
I assume Mascheroni did more than this for many authors to use "Euler-Mascheroni" for the name of $\gamma$ ? Any information on what his contribution was would be appreciated.