Thirty Years of Milling. 



173 



The reason for this decisive success of the roller mill is 

 quite simple. It encourages the popular demand for a white 

 loaf. The millstone, in order to do its work of breaking 

 down the grain, has to get up a periphery speed of nearly 

 2,000 feet per minute,* whereas rollers work well at 800 feet 

 per minute. This sharper treatment of the grain in the stone 

 mill is accentuated by the gritty surface and by the millstone 

 furrows with their sharp edges, so that bran powder cannot 

 be avoided by the millstone treatment. In advocating gradual 

 reduction in mills Mr. Voller says :f "When the bulk of the flour 

 is produced by the operation which also cleans the bran, dis- 

 coloured flour is inevitable, hence gradual reduction scores 

 heavily on this point alone by reason of the fact that under 

 that system the bran is not finally cleaned till the bulk of the 

 flour-yielding material has been removed." 



Gradual reduction, the process of putting the grain through 

 a series of regulated rollers travelling not half as fast as the old 

 millstone, adds vastly to the miller's control of his mill and its 

 products, and in this single word control is to be found the whole 

 secret of the roller's triumph. It is to be noted how the eminent 

 technical authority speaks of " discoloured flour." The " dis- 

 colouration " is assumed to be an obvious drawback, whereas it 

 simply means a warmer or browner hue, which is due to a 

 certain small admixture of a harmless and, indeed, valuable 

 food. The trouble with the stone mill is not that it turns out 

 innutritious flour — the very contrary is the case — but that the 

 miller has an imperfect control of what it turns out. 



It has been said that the twofold aim of all good milling is to 

 produce bran without flour, and flour without bran ; but this 

 excellent dictum is too often read as though it meant that the 

 modern loaf should contain not a speck of anything but the 

 whitest flour. 



It is sometimes asked if it be not possible to modify the mill- 

 stone so as to enable it to meet the modern requirements, but 

 the limit of possibilities is rigid. The illustration shows a 

 typical millstone, the diameter of which may be anything from 

 two to six feet — four feet would be about an average. It is 



* Modem Milling^ by W. R. Voller, p. 390. f Idem., p. 392. 



