I'kESlDK.N'JlAI, ADDRESS — SECTION A. 53 



the inlliKMicc u! a caialv >t, and iJo.cxx) ions arc said to have 

 hecn produccHl by ilii> imihod in 1914; with tlic extensions in 

 ])rogress, the \ ieUl w ill he hrought up to 300,000 tons per annum. 

 Tar is not contemplated as one of the products at the Natal 

 works, hecause the object is the maxinuun production of am- 

 uionir.ni sulphate, and the coal is said to be anthracitic; but why 

 waste a national asset in the way proposed, by allowing thou- 

 scukIs of horse-power to be ruthlessly destroyed? 



I'uzvdercd Fuel Firing. — This is an ideal system for the effi- 

 cient combustion of coal. It is in use for firing the eement kilns 

 at Pretoria and X'entersburg Road cement works, and is becoming 

 common in metallurgical works generally. It is the system 

 adopted in the Bettington boiler (the ])rinrip]c of which is shown 

 in Fig. 30). which has been installed at various works and 

 mines in South Africa. It has the great advantage, from the 

 fuel economy point of view, that it can utilise coal of a very 

 ])oor quality, and from the power station point of view that 

 steam may be got up in 20 minutes. Tests made by me, assisted 

 i)y the students of the S.A. School of Tvlines and Technology, 

 through the courtesy of Prof. Dobson, M.Sc, M.Eng., the 

 General ^Manager, on two boilers of approximatelv 3.000 h.p. 

 each, one a marine type Babcock & Wilcox, as used by the Vic- 

 toria Falls and Transvaal Power Co., and the other a Bettington 

 boiler, both at the power station of Johannesburg Municipalitv. 

 gave the following results : — 



TABLE Xlll. 

 Results of Tests made on the Robeson-Bettington 



BOILER AXD THi: ]>AI5COCK AND WiLCOX MARIN)-. TyPE 



Boii.ek. 



