To each two pounds of pears use a pound of cranberries, and a pound of sugar to each pound of fruit. Place the cranberries in a preserving kettle and cover with water, using a quart of water to each pound of fruit Stew until tender, then pass through a sieve. Pare, core and quarter medium-sized pears and weigh. Add the sugar to the cranberry juice and boil to a rather thick syrup, then add the pears. Let the mixture simmer until tender and of a uniform color, then fill into preserve jars with a strainer. Let the syrup boil until it begins to jelly; pour over the fruit and seal.