The Boy Mechanic, vol. 1, page 338
Take a piece of very clear ice and melt it down into the hollow of your hands so as to form a large lens. The illustration shows how this is done. With the lens-shaped ice used in the same manner as a reading glass to direct the sun's rays on paper or shavings you can start a fire. - Contributed by Arthur E. Joerin.
“Consequently, faith comes from hearing the message, and the message is heard through the word of Christ.”
– Romans 10:17