CANDLE. Candles can be made from any fatty substance which, at ordinary temperatures, is in a solid state ; wax, spermaceti, and tallow being the usual substances employed. That very essen tial part of a candle, the wick, performs an office which involves a scrap of philo sophy not always well understood. The wick is composed of a dozen or more fibres of soft cotton, ranged side by side, and having just sufficient twist given them to make them cling together. The threads are not so close together trat that oil, or tallow in a melted state, will as cend between them, by virtue of that ca pillary attraction which will cause a piece of loaf-sugar to become wet throughout, if placed on a wet spot. When a candle is lighted, the heat melts the upper part of the tallow, which then ascends between the fibres of the wick, and furnishes minute streams of combustible matter as fast as the oxygen of the air will consume it in the form of flame. The current of air constantly supplying oxygen, keeps the outer surface of the tallow cool, and causes the formation of the cup which contains the melted tallow that other wise would run down and disfigure the candle : the tallow is the combustible matter, and the wick is the series of tubes through which it ascends to the flame. Wax candles are made by pouring melted wax over the wicks, which for the convenience of turning and placing them successively over the caldron, are usually attached to the circumference of a hoop ; when of a proper thickness, they are rolled smooth upon a table, and the ends are cut and trimmed. It is iu con sequence of this method of manufacture, that when we cut a wax candle we ob gerve it composed of successive layers or costa. Attempts have been made to cast -wax candles in moulds, but those which are thus made never burn so well as those which are poured. Spermaceti can dles, are mixtures of wax and spermaceti. This material forms a very good and cleanly candle ; but in consequence of its ready fusibility and hardness when con crete, it does not admit of being carried about without spilling the melted mate rial. The fused portions also, which run
down the candle, are apt to curl and fall upon the table. Composition candles. This term was originally conferred by a manufacturer who had a large stock of spermaceti candles on hand which were of a dirty hue, and which therefore were unsalable ; he advertised them under the above name, and they were soon dis posed of, under the notion of their being composed of some new combination of materials. The term has since been ap plied to various mixtures ; but what are now sold under the name of composition candles are chiefly mixtures of sperma ceti, tallow, and a little resin, and occa sionally wax. Tallow candles, which are either east upon the wick in pewter moulds, or made by dipping the wicks, attached in rows to proper frames, into melted tallow. Steartne candles. Under this term we may include cocoa-nut oil candles, and a few others made of the stearine, or what may be compared to the spermaceti of the vegetable oils. The stearine, or rather the stearic acid of tal low, is also now extensively- employed for making candles. ifould candles are made in two ways. 1. From ten to six teen cylindrical pewter moulds are placed together in a wooden frame, so that their upper ends terminate in a kind of trough common to the whole. The wicks are inserted and kept firmly in their proper places in the centre of each cylinder by strong wires. The frame being then placed with the trough uppermost, the moulds are filled with melted tallow, and are placed in the air to cool, after which the wires by which the wicks have been fixed are withdrawn, the superfluous tal low is removed from the trough, and the candles are pulled out of the moulds.
In the following illustration of a mould candle machine, a represents the candle, b the mould through which the candles are pushed by the rod c.