For each soup bowl use 2½ glasses of water of which at least 1 glass must boil away. For 6 people, therefore, use 15 glasses or 5 bottles of water, from which 6 glasses or 2 bottles of water must boil away. Place the beef in the soup kettle and pour over it 6 full soup dishes or 9 glasses of water. Measure the height of the water with a clean, smoothly planed spill* or stick. Mark the stick and add the remaining water. Cook the bouillon for 3–4 hours, by which time it should be reduced to the mark on the stick.