Setting up Log4Net to log output from a Class Library

I'm trying to setup Log4Net (this is my first time using Log4Net) to log to a text file in an assembly. I'm not getting any errors, but it's also not working. I can breakpoint the lines where I am logging my output and see that they are reached, but like I say nothing happens.

Where am I going wrong?

I have added the following to my packages.config file, inside the <packages> attribute:

  <log4net>
    <appender name="FileAppender" type="log4net.Appender.FileAppender,log4net">
      <file value="c:\CTI\log.txt" />
      <appendToFile value="true" />
      <lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %level %logger - %message%newline" />
      </layout>
      <filter type="log4net.Filter.LevelRangeFilter">
        <levelMin value="INFO" />
        <levelMax value="FATAL" />
      </filter>
    </appender>

    <root>
      <level value="DEBUG"/>
      <appender-ref ref="FileAppender"/>
    </root>
  </log4net>
</configuration>

I have added the following line to AssemblyInfo.cs:

[assembly: log4net.Config.XmlConfigurator(Watch=true)]

I added the Log4Net assembly using NuGet and I am logging like this:

private log4net.ILog _Log;
_Log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
_Log.Debug("FooBar");

Like I say, no errors but nothing happens either.

What am I missing?