Charting: Chart not visible

I have a simple programmatically designed test chart chart1 in my WinForm Form1 which displays fine.

When I then move the chart design method to a separate class and call it from main (to become chart2) it is present in Form1 as a blank chart, but the series do not show.
(Chart2 has no chartareas or series of its own).

All charts properties are in the called method: Chart area, series, points, etc. but the chart area remains empty.

Help will be appreciated.

When run in Form1: (displays OK)

using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;


namespace Charting
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        drawChart drawchart = new drawChart();   //<

        private void button1_Click(object sender, System.EventArgs e)
        {
            //this.chart2 = drawchart.draw();    //<< This is the call to the other class


            ChartArea ChartArea1 = new ChartArea();


            this.chart2.ChartAreas.Add("ChartArea1");
            this.chart2.Series.Add("series");
            this.chart2.Series[0].Points.AddXY(1, 5);
            this.chart2.Series[0].Points.AddXY(2, 4);
            this.chart2.Series[0].Points.AddXY(3, 3);
            this.chart2.Series[0].Points.AddXY(4, 2);
            this.chart2.Series[0].Points.AddXY(5, 1);
            this.chart2.Show();
        }
    }
}

When run in class drawChart: (Displays Empty chart)

using System.Windows.Forms.DataVisualization.Charting;


namespace Charting
{
    class drawChart
    {


        Chart chart1 = new Chart();
        public Chart draw()
        {


            ChartArea ChartArea1 = new ChartArea();
            this.chart1.ChartAreas.Add("ChartArea1");
            this.chart1.Series.Add("series");
            this.chart1.Series[0].Points.AddXY(1, 5);
            this.chart1.Series[0].Points.AddXY(2, 4);
            this.chart1.Series[0].Points.AddXY(3, 3);
            this.chart1.Series[0].Points.AddXY(4, 2);
            this.chart1.Series[0].Points.AddXY(5, 1);


            return chart1;
        }
    }
}