On the other hand the city is not in such a fortunate position. It will have to forget a good deal of what it has assimilated in connection with the disposal of the contents of the ash-barrel. A change-over from the old to the new method must inevitably occupy time, especially as those two dragging chains which always retard the march of progress--prejudice and conservatism--have first to be released. Nevertheless, as destruction of domestic waste by fire superseded dumping upon open land, so must incineration, in turn, give way to the latest demands of science and the immutable economic law. The dust destructor never could possibly be construed into a scientific solution of the problem: it has no constructional or creative value, except of a nuisance in the form of accumulations of clinker. Even primitive dumping upon the land did possess the distinct advantage of benefiting the soil over which it was distributed. When the latest idea for recovering and exploiting the by-products of the dust-bin achieves the vogue which it deserves, land and industry will profit to the benefit of the community and of the country. Naturally, certain local authorities, notoriously opposed to progressive development, will seek to stop the tide by belittling the new policy. They have become so firmly wedded to the destructor in which so much of the ratepayers’ money has been sunk as to be blind to improvement. They will continue still to waste money in supporting their fetish, strenuously declining to honour the axiom that it is often cheaper to cut the loss. In the absence of willingness to jettison the old and to adopt the new, the pressure of compulsion should be applied. Local authorities must be prevented from continuing to squander potential resources of raw material. Alternatively, the exploitation of the despised dust-bin should be brought within the reach of private enterprise, which should be extended every encouragement. Other nations have always regarded our much-vaunted dust destructor as the high-road to waste. It has never found any pronounced favour beyond the confines of Britain. Have our rivals been wiser than we? An interesting commentary upon this somewhat inexplicable predisposition to destruction by fire is offered by the experience of the city of San Francisco. In 1896 the city granted a fifty years’ franchise for the provision of a destructor for the disposal of household refuse to a private party. “This destructor,” remarks the city engineer in a communication to myself, “is the second, and last, example of the Thackery furnace and arrangement, the first having been built in Montreal, Canada, the previous year (1895).”