Font size of the text in a DBGrid

Please look at the sql in the related question for more info. Basically I have made the column width to a fixed number(70). It is too small to hold the entire Ip address if each octet is 3 digits. So how can I make the text that appears in the cells smaller? I tried the following, but did not work:
procedure TDNSForm.GatewayGridDrawColumnCell(Sender: TObject;
  const Rect: TRect; DataCol: Integer; Column: TColumn;
  State: TGridDrawState);
begin
  if Column.Field.DataSet.RecNo = 1 then
  (Sender as TDBGrid).Canvas.Font.Color := clMedGray
  else
  //(Sender as TDBGrid).Canvas.Font.Size := 2; // This line did not work either
  Column.Font.Size := 4;
  GatewayGrid.DefaultDrawColumnCell(Rect, DataCol, Column, State);
end;