Engineering Wonders of the World
Volume III

THE MODERN DESTRUCTOR. BY F. L. WATSON, M.I.Mech.E., A.M.Inst.C.E. THE disposal of the rubbish of cities by burning was known and practised by the ancients, a fact which can be proved by many classical and Biblical quota- tions. During the Dark Ages, however, all systematic sanitary work fell into disuse, and the disposal of refuse was left to the indi- vidual, who easily solved the difficulty by depositing it in the public street. When modern civilization brought with it the organization of public cleansing, in some countries the system was adopted of appoint- ing a public contractor, who had a right to charge each householder for the removal of his rubbish ; in others the householders united to employ their own contractors; and in others, again, the municipality undertook the collec- tion and disposal of rubbish either by employ- ing a contractor or by using its own means of transport and employing direct labour. Collection and disposal by the municipality is now the general rule in England and in Germany, and to a great extent in France ; but in the United States collection and removal by contractors is prevalent. Until quite recently it was the universal custom of municipalities to deposit the rub- bish thus collected in tips, using it to fill up The Old System of Disposal. old brick pits and hollow spaces, and for raising and re- claiming waste or marshy land. Where suitable land is avail- able a great deal of town refuse may be use- fully employed in this way, provided the dis- tance is not too great; but the tipping of refuse in any area included in the possible growth of a city, and which may become building land, ought to be entirely prohibited, because this material will for many years go on fermenting and producing noxious germs whose deleterious action can only be pre- vented by the natural process of growing crops on the surface. It is evident, therefore, that municipalities, especially of large cities, are being more and more driven to adopt the complete and final disposal of their rubbish by the most ancient and perfect of purifying agents — namely, fire. When special furnaces were first introduced for this purpose in England they were very crude affairs, erected by the local bricklayer without any regard for the science of com- bustion. In due course, however, the design- ing and building of destructors became recog- nized as an important branch of engineering, and there are now a number of engineers who devote all their attention to this subject. The result has been that the destructor of to-day has become a highly scientific and very useful apparatus, and one in which enlightened muni- cipalities are prepared to invest very large sums of money. The most important step on the upward march occurred when the principle of forced draught, embodied from time immemorial in the blacksmith’s fire, was ap- plied to the destructor. The Forced immediate result was to pro- ^>rau^ht. duce rapid combustion and a high tempera- ture, and to prove that all classes of ordinary town rubbish are, with very few exceptions, auto-combustible or capable of burning with- out added fuel. The high temperature pro- duced by this improvement led to the idea that the heat evolved could be utilized, and this was done by putting a small boiler in the flue of the destructor and using the steam