The Nineteenth Hole

This is part of a "Preparation and Properties of Oxygen" lab, where we must "demonstrate the collection of a gas by water displacement and to investigate the chemical and physical properties of oxygen". We had to "roll a piece of steel wool into a cylindrical shape about 10 cm long and 0.5 cm in diameter. Take out the last bottle of oxygen and add enough water to cover the bottom to a depth of about 2.5 to 3.5 cm. Hold the steel wool with the tongs, heat it for a second or two with the bunsen burner and then thrust it into the oxygen in the bottle." When we put the hot steel wool into the bottle of oxygen, it sparked a lot, and the only thing that I know if if you don't add water or add enough water, the glass bottle will crack.