This section is from the book "Economical Cookery", by Marion Harris Neil. Also available from Amazon: Economical Cookery (1918).
Apples Salted cold water
Canning by cold pack method is not difficult. Wash jars and rubbers and test rubbers for quality. Set empty jars and rubbers in pan of water to heat to boiling point and boil ten minutes. Fill a wash boiler to cover jars two inches with water and heat this water. Pare, core, and slice sound apples, and drop them into slightly salted cold water. Put apples into wire basket or piece of cheesecloth and dip for one and one half minutes into plenty of boiling water. Plunge immediately into cold water and then pack into hot jars. Fill up jars with hot sirup or boiling water; put rubbers and tops in position and partially tighten tops. Place jars on rack in wash boiler and submerge them two inches. Place cover on boiler and let water boil twenty minutes. Lift out jars and make tops air-tight. Invert jars to discover leaks. If leaks are found, change rubbers and boil again five minutes.
To Make Sirup. Put three quarts sugar into a saucepan, add three quarts water, and boil until sugar is thoroughly dissolved. Skim off impurities and keep sirup hot.