Using magnifying glass to start fires instead of matches or lighters on a sunny day

If you intend to start a fire on a hot sunny day to barbecue outdoors or for other kind of cooking, you can do it without using up matches and lighters. Simply pile up the coal or wood you want to burn and focus a magnifying glass on it as pictured below:

It is advisable to place a used piece of paper or pour a bit of flammable liquid to start the fire more easily, but not at all necessary. By using a magnifying glass you save matches and lighter fuel.

But note that it must be a hot day with intense sunlight in order for this to happen.