“With regard to lighting arrangements, an original natural lamp used here until quite recently was the “Tanrogan,” or large scallop, the hollow upper shell of which made a natural saucer in which a wick of rag or rush would lie in solid or liquid grease, sometimes lard, sometimes fish oil or goose grease.
The “Cruisie” is very rare. It has an oil vessel formed with a spout from which the wick “bitte” projects, and hangs from a hook provided with notches by means of which the vessel can be tipped forward gradually as the oil burns. A second and larger vessel fixed below is to catch the dripping of the oil.
The iron rush and candle holder is more common but fast disappearing. For these rushes were cut in the summer, the peel removed excepting a narrow rib running from top to bottom, left to support the pith, and the cores thus obtained dried and bleached in the sun, while the strips of peel were twisted to form lankets for sheep. The cores were then dipped in scalding grease until thoroughly saturated and after being allowed to cool, were ready to use. The most simple type of iron holder for these rushlights had a thin point of the iron, about an inch long, split off for the purpose; a further development was for the top to fork, the ends turning over. The total height of the holders was generally from 9 to 12 inchs; sometimes the stem is set on three or four iron legs instead of in the wooden block.”
(source: Manx Antiquities by PMC Kermode & WA Herdman, 1914)