128 CONSTRUCTION AND MANAGEMENT OF SMALL (IAS WORKS. 



CHAPTER XII. 



THE DISPOSAL AND UTILIZATION OF RESIDUALS. 



THERE is rather too much of a disposition in small works to 

 let the residuals take care of themselves. There is always 

 something to be done in the way of improving the market 

 for them. Of course, in works of the size under con- 

 sideration, such operations must be on a simple scale, as 

 mechanical power is out of the question, and the small 

 amount of material to be handled precludes anything of a 

 costly or elaborate nature. A small hand coke breaking 

 machine is usually a good investment ; and something can 

 be done in the way of manufacturing tar asphalt, both with 

 the aid of the waste ashes on the works, or with stone 

 chippings purchased for the purpose. The material can be 

 thoroughly dried in a warm corner of the retort house and 

 the tar boiled in a small portable boiler. Really good tar 

 asphalt cannot be made without thoroughly drying and 

 warming the aggregate and boiling the tar. If there is any 

 difficulty in getting rid of the tar, or the cost of carriage 

 bulks largely as compared with the price received, the 

 supply of asphalt, laid complete for playgrounds, coach- 

 houses, yards, garden walks, foot walks, etc., is well worth 

 consideration. 



The usual plan is to run the whole of the liquid products 

 into one store well, and trust to the separation of the tar by 



