LAMPS. Receptacles in which oil is burned by means of a wick, and used as an illuminating power. There was a time when lamps seemed destined to be entirely superseded by gas, but recently, in consequence of the high charge for gas and the great improvement in kerosene and in the lamps themselves they have again come into favor and are used to a noticeably large extent. The Argand lamp, which was invented nearly one hun dred years ago, was the first great novelty in principle, and consists of a circular wick through which a current of air passes. Grocers who use them for lighting their stores should have the best and keep them in the very best condition, as no stock needs as much light as the grocer's. But a decided improvement on lamps would be to close the store earlier and so dispense with their use, which would be more generally done if the expense of light, heat and time was accurately compared with the small sales made after seven o'clock.
Why Lamps Explode. An exchange says all explosions of petroleum lamps are caused by the vapor or gas that collects in the space above the oil. Of course, the lamp contains no gas, but immediately on lighting the lamp consumption of oil begins, soon leaving a space for gas, which commences to form as the lamp warms up, and after burning a short time sufficient gas will accu mulate to cause an explosion. The gas in a lamp will explode only when ignited. In this respect it is like gunpowder. Cheap or inferior oil is always the most dangerous. The flame is com municated to the gas in the following manner : The wick-tube in the lamp-burner is made larger than the wick which is to pass through it. It would not do to have the wick work tightly in the
burner ; on the contrary, it is essential that it move up and down with perfect ease. In this way it is unavoidable that space in the tube is left along the side of the wick sufficient for the flame from the burner to pass down into the lamp and explode the gas. Many things occur to cause the flame to pass down the wick and ex Diode the lamp : 1. A lamp may be standing on the table or mantel, and a slight puff of air from the open window or door may cause an explosion. 2. A lamp may be taken up quickly from a table or mantel and instantly explode. 3. A lamp is taken into an entry where there is a draught, or out of doors, and an explo sion ensues. 4. A lighted lamp is taken up a flight of stairs, or raised quickly to place it on the mantel, resulting in an explosion. In these instances the mischief is done by the air movement, either by suddenly checking the draught or forcing air down a chimney against the flame. 5. Blowing down the chimney to extinguish the lamp is a frequent cause of explosion. G. Lamp explosions have been caused by using a chimney broken off at the top or one that has a piece broken out, whereby the draught is variable and the flame unsteady. 7. Sometimes a thoughtless person puts a small sized wick in a large burner, thus leaving considerable space along the edges of the wick. 8. An old burner, with its air draughts closed up, which rightfully should be thrown away, is sometimes continued in use, and the final result is a disastrous explosion.