How to write events from multiple applications(sources) to the same event log?

See more:

C#

I have created a custom event log and would like all my applications to write to the same event log. (You will be able to see that happen in your Event Viewer in Windows Logs.)
Similarly, I have 2 services that I want to write to the same eventLog. I tried doing that by creating one event log and passing different source names from the 2 Windows Services that I have created. But I find only one Service writing to the log while the other doesn't.

Also, when I try to stop the services, Service 1 fails to stop and throws an error.
The error reads "Windows could not stop the <servicename> service on Local Computer. Error 1061: The service cannot accept control messages at this time."

What I have tried:

Below is the class library that I created for Event Log.

public class EventLogger
{
    private EventLog eventLog1 = new System.Diagnostics.EventLog();

    public EventLogger(string logSource)
    {
        if (!System.Diagnostics.EventLog.SourceExists(logSource))
        {
            System.Diagnostics.EventLog.CreateEventSource(logSource, "SampleLog");
        }
        eventLog1.Source = logSource;
        eventLog1.Log = "SampleLog";
    }

    public void WriteLog(string message)
    {
        eventLog1.WriteEntry(message);
    }
}

Created 1st Windows Service

public partial class Service1 : ServiceBase
{
    private EventLogger.EventLogger eventLog;
    public Service1()
    {
        InitializeComponent();
        eventLog = new EventLogger.EventLogger("WinService1");
    }

    protected override void OnStart(string[] args)
    {
        try
        {
            eventLog.WriteLog("Service started in 1st");
        }
        catch (Exception ex)
        {
            EventLog.WriteEntry(ex.ToString());
        }
    }

    protected override void OnStop()
    {
        eventLog.WriteLog("Service stopped");
    }
}

Created the 2nd windows Service as well, as above.

public partial class Service2 : ServiceBase
{
    private EventLogger.EventLogger eventLog;
    public Service2()
    {
        InitializeComponent();
        eventLog = new EventLogger.EventLogger("WinService2");
    }

    protected override void OnStart(string[] args)
    {
        try
        {
            eventLog.WriteLog("Service started in 2nd");
        }
        catch (Exception ex)
        {
            EventLog.WriteEntry(ex.ToString());
        }
    }

    protected override void OnStop()
    {
        eventLog.WriteLog("Service stopped");
    }
}

Service1 doesn't seem to log anything, whereas, I can see the logs for Service2. I might be doing a lot of things incorrectly here. Please help me in finding a solution to this. Also, if this can be achieved by using log4Net then solutions with respect to that are welcome as well. thanks in advance.