STERILIZATION 



201 



I must refer to special treatises for details of modern dust 

 destructors. The different types have been adapted in different 

 places to local requirements, and portable destructors are made 

 for thinly-populated places, camps, etc. In Midland towns, 

 where privy middens still exist, their contents have been suc- 

 cessfully passed through the destructors along with the ordinary 

 dust. 



Wherever possible, the combination of a destructor plant for 

 town refuse with the sewage disposal works has great advan- 

 tages for the following reasons : (i) The power derived from 

 the burning of the refuse, though not so great as has sometimes 

 been hoped, is available for the pumps and machinery of the 

 sewage works. In this way a scheme that would be preferred 

 but for the cost of pumping is frequently rendered practicable. 

 (2) Larger organic ddbris screened from the sewage can be 

 burned in the destructor. (3) The clinker from a properly- 

 worked destructor can be used in paving construction, and as 

 a material for filter-beds. (4) A site chosen as suitable for 

 sewage works will also be suitable for a destructor, and the 

 management of the two require similar precautions as to public 

 health. The apparent difficulty of carriage of the town refuse 

 to the works has not been insuperable. As in towns the ratio 

 of the volume of the sewage to that of the solid refuse is more 

 or less constant, it follows that when the steam-raising efficiency 

 of a given type of destructor is known, the height to which the 

 town sewage can be lifted by power derived from the destructor 

 is fixed. 



