Here on page 2 we will get some more background on this tool. According to our war veteran at Graywolf Survival:
Cooking is a rather natural use for solar power. We all know how the sun warms things that it strikes, leaving the inside of our cars hot and making ussweat on a sunny day. Many of us have also played with magnifying glasses as kids, using them to light dried leaves and scraps of paper on fire. That power can be harnessed in a more structured way, making it extremely easy to cook with. Scientists have built solar furnaces which are hot enough to melt iron. While you don’t need anything quite that hot, a simple solar cooker could be a great piece of survival equipment to add to your collection. There are several different designs of solar cookers you can make, but the most effective uses a Fresnel lens. Fresnel lenses are flat plastic magnifying glasses. If you’ve ever used one of those sheet magnifiers, you’ve used a Fresnel lens. They consist of a flat plastic sheet that has concentric rings molded into the back side. The rings act in the same manner as a regular magnifying glass, with the exception that each ring is a separate thin magnifier. To get full instructions on how to build this bad boy, see our article and image source at Graywolf Survival. And as usual, please give us your feedback if you try this at home.
Michael Ryan