have lain dormant, lingering here and there, chiefly in old-fashioned houses, and almost forgotten.
Again, why should a layman, whose profession lies outside that of the architect, the builder, and the manufacturer, take upon himself to teach principles that are to guide other professions than his own? Mainly for two reasons: one, that there are principles which a medical man may work out without reproach, as tending to contribute to the happiness, the comfort, and the health of mankind; the other, that when principles have to be insisted upon, and to be made a subject of public instruction, they can be urged with more effect by those who are hampered by no relations to any patents, and have no pecuniary interest in the success or failure of the application of the principles in question. On this point we have a good example in Count Rumford, who says in a note: "The public in general and particularly those tradesmen and manufacturers whom it may concern, are requested to observe that, as the author does not intend to take out any patent for any invention of his which may be of public utility, all persons are at full liberty to imitate them, and vend them for their own emolument, when, and where, and in any way they may think proper."
Three evils result from the prevalence of bad principles in construction: 1. Waste of fuel and loss of heat. 2. Excessive production of soot and smoke. 3. Large addition to ash-pit refuse by cinders, which are really unburned, and therefore wasted fuel. These are matters of national concern, and it has been the main object of my labors on this question during the last four years to endeavor to convince the public that it is the interest no less than the duty of every house-holder to burn his fuel on correct principles, and to do his part toward the diminution of these evils.
On the first point, "waste of fuel and heat," let us listen to Rumford, whose words are as true to-day as when written eighty years ago: "Though it is generally acknowledged that there is a great waste of fuel in all countries, arising from ignorance and carelessness in the management of fire, yet few—very few, I believe—are aware of the real amount of this waste. . . . From the result of all my inquiries upon this subject, I have been led to conclude that not less than seven eighths of the heat generated, or which with proper management might be generated, from the fuel actually consumed, is carried up into the atmosphere with the smoke, and totally lost. . . . And with regard to the economy of fuel, it has this in particular to recommend it, that whatever is saved by an individual is at the same time a positive saving to the whole community."
Heat is wasted in three ways—either by combustion under the impulse of strong draught, which means rapid escape of heat up the chimney; or by imperfect combustion of the gases which are generated during the burning of the coals; or by escape of heat through the iron sides and back into the space between the range and the
