The 8 Step: Put the white nitre into iron pan to cook with suitable quantity water, wait to become the powder.
The 9 Step: Cooking brim stone
The 10 Step: Grind the nitre put the nitre into stone mill to become the powder. According to the proportion of weight, match into the cedar leaf powder and sulfur.
The 11 Step: Make the effect tubes : put the clay into inner tubes, next to put the powder into inner tubes.
