Page:EB1911 - Volume 10.djvu/570

Rh mentions some 500 mills in the counties of Norfolk and Suffolk alone. No doubt the mola of Domesday Book consisted of one pair of stones connected by rude gearing with a water-wheel. Windmills are said to have been introduced by the Crusaders, who brought them from the East. Steam power is believed to have been first used in a British flour mill towards the close of the 18th century, when Boulton & Watt installed a steam engine in the Albion Flour Mills in London, erected under the care of John Rennie. Another great engineer, Sir William Fairbairn, in the early days of the 19th century, left the impress of his genius on the mill and all its accessories. He was followed by other clever engineers, and in the days immediately preceding the roller period many improvements were introduced as regards the balancing and driving of millstones. The introduction of the blast and exhaust to keep the stones cool was a great step in advance, while the substitution of silk gauze for woollen or linen bolting cloth, about the middle of the 19th century, marked another era in British milling. Millstones, as used just before the introduction of roller milling, were from 4 to 4 ft. in diameter by some 12 in. in thickness, and were usually made of a siliceous stone, known as buhr-stone, much of which came from the quarry of La Ferté-sous-Jouarre, in France.

Nine-tenths, or perhaps ninety-nine hundredths, of all the flour consumed in Great Britain is made in roller mills, that is, mills in which the wheat is broken and floured by means of rollers, some grooved in varying degrees of fineness, some smooth, their work being preceded

and supplemented by a wide range of other machinery. All roller mills worthy of the name are completely automatic, that is to say, from the time the raw material enters the mill warehouse till it is sacked, either in the shape of finished flour or of offals, it is touched by no human hand.

The history of roller milling extends back to the first half of the 19th century. Roller mills, that is to say, machines fitted with rolls set either horizontally, or vertically, or obliquely, for the grinding of corn, are said to have been used as far back as the 17th century, but if this be so it is certain that they were only used in a tentative manner. Towards the middle of the 19th century the firm of E. R. & F. Turner, of Ipswich, began to build roller mills for breaking wheat as a preliminary to the conversion of the resultant middlings on millstones. The rolls were made of chilled iron and were provided with serrated edges, which must have exercised a tearing action on the integuments of the berry. These mills were built to the design of a German engineer, of the name of G. A. Buchholz, and were exhibited at the London exhibition of 1862, but they never came into general use. It has also been stated that as early as 1823 a French engineer, named Collier, of Paris, patented a roller mill, while five years later a certain Malar took out another French patent, the specification of which speaks of grooves and differential speeds. But the direct ancestors of the roller mills of the present day were brought out some time in the third decade of the 19th century by a Swiss engineer named Sulzberger. His apparatus was rather cumbrous, and the chilled iron rolls with which it was fitted consumed a large amount of power relatively to the work effected. But the Pester Walz-Mühle, founded in 1839 by Count Szechenyi, a Hungarian nobleman, which took its name from the roller mills with which it was equipped by Sulzberger, was for many years a great success; some of its roller mills are said to have been kept at work for upwards of forty years, and one at least is preserved in the museum at Budapest.

It may be noted that Hungarian wheat is hard and flinty and well adapted for treatment by rolls. Moreover, gradual reduction, as now understood, was more or less practised in Hungary, even before the introduction of roller milling. Though millstones, and not rolls, were used,

yet the wheat was not floured at one operation, as in typical low or flat grinding, but was reduced to flour in several successive operations. In the first break the stones would be placed just wide enough apart to “end” the wheat, and in each succeeding operation the stones were brought closer together. But Hungarian milling was not then automatic in the sense in which British millers understand the word. For a long time a great deal of hand labour was employed in the merchant mills of Budapest in carrying about products from one machine to another for further treatment. This practice may have been partly due to the cheap labour available, but it was also the deliberate policy of Hungarian millers to handle in this way the middlings and fine “dunst,” because it was maintained that only thus could certain products be delivered to the machine by which they were to be treated in the perfection of condition. The results were good so far as the finished products were concerned, but in the light of modern automatic milling the system appears uneconomical. Not only did it postulate an inordinately large staff, but it further increased the labour bill by the demand it made on the number of sub-foremen who were occupied in classifying, largely by touch, the various products, and directing the labourers under them. Hungarian milling still differs widely from milling as practised in Great Britain in being a longer system. This is due to the more minute subdivision of products, a necessary consequence of the large number of grades of flour and offals made in Hungary, where there are many intermediate varieties of middlings and “dunst” for which no corresponding terms are available in an English miller’s vocabulary.

It will be convenient here to explain the meaning of three terms constantly used by millers, namely, semolina, middlings and dunst. These three products of roller mills are practically identical in composition, but represent different stages in the process of reducing the endosperm

of the wheat to flour. A wheat berry is covered by several layers of skin, while under these layers is the floury kernel or endosperm. This the break or grooved rolls tend to tear and break up. The largest of these more or less cubical particles are known as semolina, whilst the medium-sized are called middlings and the smallest sized termed dunst. The last is a German word, with several meanings, but is used in this particular sense by German and Austrian millers, from whom it was doubtless borrowed by the pioneers of roller milling in England. If we were to lay a sample of fairly granular flour beside a sample of small dunst the two would be easy to distinguish, but place a magnifying glass over the flour and it would look very like the dunst. If we were to repeat this experiment on dunst and fine middlings, the former would under the glass present a strong resemblance to the middlings. The same effect would be produced by the putting side by side of large middlings and small semolina. This is a broad description of semolina, middlings and dunst. Semolina and middlings are more apt to vary in appearance than dunst, because the latter is the product of the later stages of the milling process and represents small particles of the floury kernel tolerably free from such impurities as bran or fluff. The flour producing middlings must not be confounded with the variety of wheat offal which is also known to many English millers as middlings. This consists of husk or bran, more or less comminuted, and with a certain proportion of floury particles adherent. It is only fit for feeding beasts.

The spread of roller milling on the continent of Europe was undoubtedly accelerated by the invention of porcelain rolls, by Friedrich Wegmann, a Swiss miller, which were brought into general use in the seventh decade of the 19th century, and are still widely employed. They are

admirably fitted for the reduction of semolina, middlings and dunst into flour; and for reducing pure middlings, that is, middlings containing no bran or wheat husk, there is perhaps nothing that quite equals them. They were introduced into Great Britain in 1877, or thereabouts, and were used for several years, but ultimately they almost disappeared from British mills. This was partly due to the fact that as made at that date they were rather difficult to work, as it was not easy to keep the rolls perfectly parallel. Another drawback was their inadaptability to over-heavy feeds, to which the British, and perhaps still more the American, miller is frequently obliged to resort. However, since the beginning of the 20th century some of the most advanced flour mills in England have again