DEGREES OF HEAT FROM FUEL. Willow charcoal 600° _Fah._ Ordinary charcoal 700° _Fah._ Hard wood 800° to 900° _Fah._ Coal 1000° _Fah._ _Lights_ are next in order. Gas hardly requires mention, as the care of it is limited to seeing that it is not turned too high, the flame in such case not only vitiating the air of the room with double speed, but leaving a film of smoke upon every thing in it. Kerosene is the oil most largely used for lamps; and the light from either a student-lamp, or the lamp to which a "student-burner" has been applied, is the purest and steadiest now in use. A few simple rules for the care of lamps will prevent, not only danger of explosion, but much breakage of chimneys, smoking, &c. 1. Let the wick always touch the bottom of the lamp, and see that the top is trimmed square and even across, with a pair of scissors kept for the purpose. 2. Remember that a lamp, if burned with only a little oil in it, generates a gas which is liable at any moment to explode. Fill lamps to within half an inch of the top. If filled brimming full, the outside of the lamp will be constantly covered with the oil, even when unlighted; while as soon as lighted, heat expanding it, it will run over, and grease every thing near it. 3. In lighting a lamp, turn the wick up gradually, that the chimney may heat slowly: otherwise the glass expands too rapidly, and will crack. 4. Keep the wick turned high enough to burn freely. Many persons turn down the wick to save oil, but the room is quickly poisoned by the evil smell from the gas thus formed. If necessary, as in a sick-room, to have little light, put the lamp in the hall or another room, rather than to turn it down. 5. Remember, that, as with the fire, plenty of fresh air is necessary for a free blaze, and that your lamp must be kept as free from dirt as the stove from ashes. In washing the chimneys, use hot suds; and wipe with bits of newspaper, which not only dry the glass better than a cloth, but polish it also. 6. In using either student-lamps, whether German or American, or the beautiful and costly forms known as moderator-lamps, remember, that, to secure a clear flame, the oil which accumulates in the cup below the wick, as well as any surplus which has overflowed from the reservoir, must be _poured out daily_. The neglect of this precaution is the secret of much of the trouble attending the easy getting out of order of expensive lamps, which will cease to be sources of difficulty if this rule be followed carefully.