posted on Nov, 2 2012 @ 03:06 PM
Cool idea but not practical in a survival situation as you'd need alot of water, a big setup, and you have to wait till the sun is on the right spot.
A small magnifying glass would do the job just as good and it is a lot more practical.
and if you really don't have a magnifying glass you could also learn how to make a fire with a bow drill.
after some practice you will get the hang of it.