Many people, who are silent to the calls of humanity, are yet attentive to the voice of interest: chimneys cleansed in this way never need a tenth part of the repairs required where they are swept by children, who being obliged to work themselves up by pressing with their feet and knees on one side, and their back on the other, often force out the bricks which divide the chimneys. This is one of the causes why, in many houses, a fire in one apartment always fills the adjoining ones with smoke, and sometimes even the neighboring house. Nay, some houses have even been burnt by this means; for a foul chimney, taking fire, has been frequently known to communicate, by these apertures, to empty apartments, or to apartments filled with timber, where, of course, it was not thought necessary to make any examination, after extinguishing the fire in the chimney where it began.
136. _To revive a dull Fire._--Powdered nitre, strewed on the fire, is the best bellows that can be used.
137. _Fires, Stoves, &c._--It is wasteful to wet small coal, though it is commonly thought to make a fire last longer: in truth, it wastes the heat, and for a time makes a bad fire.
A close stove intended to warm an apartment should not have a polished surface, else it will keep in the heat; whereas, if of rough and unpolished cast iron, the heat will be dispersed through the room.
Long, shallow grates, are uneconomical, as the body of the coal in them is not soon heated, and requires to be oftener replenished to keep up the fire.
A good fire should be bright without being too hot: the best and quickest mode of making up a neglected fire is to stir out the ashes, and with the tongs fill up the spaces between the bars with cinders or half-burnt coals: this method will soon produce a glowing fire. If coke can be mixed with coals, the fire will require extra attention: coke, however, makes too much dust for fires in the best rooms.
138. _Water._--Hard water by boiling may be brought nearly to the state of soft. A piece of chalk put into spring water will soften it.
Rain, or the softest water, is better adapted than any other for washing and cleaning; but it must be filtered for drinking in large towns, as it becomes impure from the roofs and plaster of houses. The best water has the greatest number of air bubbles when poured into a glass. Hard water will become thick and foul sooner than soft water.