Peat is of vegetable origin. It is found in marshy places, and is always wet, even if not saturated with water. The roots and vegetable fibres are in different stages of decay, and the bottom layers are black, unctuous, and much more dense than the fresher growth. It is taken out in blocks, dried, and used for fuel. Air-dried peat averages about fifteen per cent, water. Peat makes much ash, the amount varying from four or five to twenty-five per cent.
The most common liquid fuels are kerosene, gasoline, and the two kinds of alcohol, - the ethyl, or common alcohol, and the methyl, or wood alcohol.
Inner Construction of Range
To use kerosene satisfactorily as a summer fuel, two things are necessary: The oil must be of good grade, -that is, have a high flashing point, - and the stove must be kept perfectly clean. The lighter oils mix readily with kerosene, and unless it is sufficiently purified to be comparatively free from these inflammable oils, there is danger of accidents in its use, just as there is danger in using oil of poor quality in a lamp. The flashing point is fixed by law, and is usually not lower than 1500, nor higher than 2000 F. With good oil, one can use a kerosene stove Very comfortably if it is cared for just as is a lamp; otherwise it will smoke and make the user very unhappy.
Diagram of a section of range, showing direction of hot-air currents when damper is open, as in No. 1; when closed, as in No. 2
Gasoline gives less trouble than kerosene, because the stove requires much less cleaning; but on account of the volatile nature of the gasoline, its use is always attended with some danger.
Both gasoline and kerosene are obtained by a process of refining the mineral oils. Most mineral oils are obtained by boring into the earth, the same as for artesian wells. In the process of refining the crude oil, the white, solid paraffine wax is obtained, and the semi-solid vaseline, as well as many products of a liquid nature, used for various purposes.
The alcohols are about equal in fuel value. They are both, when pure, colorless, volatile liquids. They ignite by the touch of a flame; give little light, much heat, and no smoke. Methyl alcohol gives off a disagreeable odor. In using either variety, the bottle should be corked and set away before a match is lighted, if one would be sure to have no accidents. Much of the ethyl alcohol is obtained from the distillation of grains. Fermentation is the only process of production. Methyl alcohol is obtained by the process known as the "destructive distillation of wood." Much of it is one of the by-products of the charcoal kiln.