For a project as in intro to a class I am taking we are making a simple solar reflector (or a transmitting lens). The restrictions are that the materials must cost less than 10 dollars, and no commercial item may be directly used for the reflective or refractive objects. Whatever you build is used to try and melt wax. My idea was to use tin foil as in the shape of a sphere to reflect the light in the middle, with a black garbage back filled with water to absorb the heat. I was also thinking about using a condom filled with water as a lens. Any thoughts/ideas?