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Primitive man was probably more concerned with fire as a source of warmth and as a means of cooking food than as a source of light. before he discovered less laborious ways of making fire, he had to preserve it, and whenever he went on a journey he carried a firebrand with him. his discovery that the firebrand, from which the torch may well developed, could be used for illumination was probably incidental to the primary purpose of preserving flame. lamps, too, probably developed by accident. early man may have had his first conception of a lamp while watching a twig or fibre burning in the molten fat dropped from roasting carcass. all he had to do was to fashion a vessel to contain fat and float a lighted reed in it. such lamps, which were made of hollowed stones or sea shells, have persisted in identical from up to quite recent times.