“She could construct a compass in no time. She needed a needle, a cup of water, and a cork that floated on the surface. She would heat a needle from one end in order to demagnetize it, put it on the cork and place them inside the cup filled with water. The heated end of the needle would point south.”

“She could construct a compass in no time. She needed a needle, a cup of water, and a cork that floated on the surface. She would heat a needle from one end in order to demagnetize it, put it on the cork and place them inside the cup filled with water. The heated end of the needle would point south.”

— Lina J. Potter