Glass Manuf. [Origin unknown.] The smooth iron rod on which the bulb of plastic glass is rolled in order to form a neck, in blowing crown-glass.
1662. Merret, trans. Neri’s Art of Glass, 365. Cranny is a round Iron whereon they roul the Glass to make the neck of it small.
1874. Knight, Dict. Mech., Cranny (Glass Manufacture), a tool for forming the necks of glass bottles.
