How to convert vinegar and similar shaped bottles into jam jars. Make a ring of strong wire large enough to slip over the neck of the bottle. Make the ring red hot, slip it over the bottle and let it rest just where you wish to cut the glass. Immerse the bottle in cold water and the top will immediately snap off, leaving an evenly cut jar.
(Women's Missionary Association of the Presbyterian Church of New South Wales, Cookery Book of Good and Tried Receipts, circa 1910)